Systems and methods for manufacturing aircraft

ABSTRACT

An aircraft manufacturing system for repetitively manufacturing aircraft comprises a first manufacturing zone configured to repetitively manufacture first aircraft subassemblies, a second manufacturing zone configured to repetitively manufacture second aircraft subassemblies, and a third manufacturing zone configured to receive the first aircraft subassemblies from the first manufacturing zone, to receive the second aircraft subassemblies from the second manufacturing zone, and to repetitively assemble the first aircraft subassemblies and the second aircraft subassemblies into the aircraft.

RELATED APPLICATION

The present application is a divisional of and claims priority to U.S.Pat. Application No. 17/505,505, which was filed on Oct. 19, 2021, andwhich claims priority to U.S. Provisional Pat. Application No.63/115,163, filed on Nov. 18, 2020. The complete disclosures of thereferenced applications are incorporated by reference.

FIELD

The present disclosure relates to systems and methods for manufacturingaircraft.

BACKGROUND

Aircraft, particularly commercial aircraft, are large, complex, anddifficult, if not impossible, to manufacture on conventional assemblylines. Instead, many of an aircraft’s large structures (e.g., wings,fuselage sections, tail, etc.) are manufactured as subassemblies atdifferent locations and subsequently brought to a central final assemblylocation. In fact, many such structures may be manufactured at locationsthat are geographically remote from each other (e.g., different cities,countries, and/or continents) by various third party suppliers and thenshipped to the aircraft manufacturer’s final assembly facility forprocessing and final assembly. Such production approaches are bothtime-inefficient and resource-inefficient. Thus, more efficientproduction techniques that produce aircraft faster (i.e. at higherproduction rates) and/or at lower cost are desired.

SUMMARY

Systems and methods for manufacturing aircraft are disclosed. Forexample, an aircraft manufacturing system for repetitively manufacturingaircraft comprises a first manufacturing zone configured to repetitivelymanufacture first aircraft subassemblies, a second manufacturing zoneconfigured to repetitively manufacture second aircraft subassemblies,and a third manufacturing zone configured to receive the first aircraftsubassemblies from the first manufacturing zone, to receive the secondaircraft subassemblies from the second manufacturing zone, and torepetitively assemble the first aircraft subassemblies and the secondaircraft subassemblies into the aircraft. In some examples, the firstmanufacturing zone, the second manufacturing zone, and the thirdmanufacturing zone are located in the same geographic region. In someexamples, one or more of the manufacturing zones includes a fractionalpulse assembly line that is configured to fractionally pulse theaircraft subassemblies by less than their length.

In another example, a method for repetitively manufacturing aircraftassemblies comprises assembling first aircraft subassemblies and secondaircraft subassemblies in parallel on separate assembly lines at acommon geographic region, and transferring the first aircraftsubassemblies and the second aircraft subassemblies to a final assemblyfacility located in the same common geographic region. In some examples,the first aircraft subassemblies are aircraft wings, and the secondaircraft subassemblies are portions of an aircraft fuselage. In someexamples, the method optionally includes sending different subassembliesand/or components thereof down the same assembly line. Additionally oralternatively, the method optionally includes fractionally pulsing oneor more of the first aircraft subassemblies and constituent partsthereof down the first assembly line and/or fractionally pulsing one ormore of the second aircraft subassemblies and the constituent partsthereof down the second assembly line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of aircraft manufacturing systemsaccording to the present disclosure.

FIG. 2 is a time-lapsed schematic representation comparing a prior artassembly line to fractional pulse assembly lines according to thepresent disclosure.

FIG. 3 is a time-lapsed schematic representation of an examplefractional pulse assembly line of the aircraft manufacturing system ofFIG. 1 .

FIG. 4 is a flowchart schematically representing methods, according tothe present disclosure, for manufacturing an aircraft at one geographicregion.

FIG. 5 is a flowchart schematically representing methods, according tothe present disclosure, for operating a fractional pulse assembly line.

FIG. 6 is a flowchart schematically representing methods, according tothe present disclosure, for forming a fractional pulse assembly line.

DESCRIPTION

Systems and methods for manufacturing aircraft are disclosed. Generally,in the figures, elements that are likely to be included in a givenexample are illustrated in solid lines, while elements that are optionalto a given example are illustrated in broken lines. Block arrowsillustrate example movement of elements in space. However, elements thatare illustrated in solid lines are not essential to all examples of thepresent disclosure, and an element shown in solid lines may be omittedfrom a particular example without departing from the scope of thepresent disclosure.

Conventionally, aircraft, particularly commercial aircraft, aremanufactured by building the large structures of the aircraft (e.g.,wings, tail, fuselage sections, etc.) separately, as discretesubassemblies, often at different geographic locations (e.g., differentcities, countries, and/or continents). These large structures are thentransferred to a central facility (also referred to herein as a finalassembly facility) where they are processed and assembled to form theaircraft. The present disclosure on the other hand, provides systems andmethods for manufacturing at least some of these large structures at onegeographic region (e.g., proximate to, adjacent to, and/or within thecentral facility), to reduce production inefficiencies and/or costs. Inparticular, manufacturing at least some of the large structures in thesame geographic region as the central facility may reduce and/oreliminate shipping times and costs. Further, in some examples, the largestructures of the present disclosure are manufactured in parallel and/orproduced at approximately the same rate at the common geographic regionso that final assembly is not delayed.

In conventional approaches, because the large structures may bemanufactured by multiple third party suppliers at various remotegeographic regions, it is difficult to synchronize the arrival times ofall the large structures at the final assembly facility. Further, thelarge structures may be unpredictably delayed for various reasonsincluding supplier manufacturing delays, shipping delays, inclementweather, etc. Since the large structurers may be manufactured bymultiple third party suppliers at many different locations around theworld, the likelihood of a delay of at least one of the large structuresis relatively high. Thus, final assembly of the aircraft may bepostponed and may not commence until all of the necessary largestructures arrive. By manufacturing the large structures in paralleland/or at approximately the same rate in the same geographic region, thepresent disclosure reduces and/or entirely eliminates final assemblydelays. That is, the systems and methods of the present disclosure maysynchronize the arrivals of the large structures at the final assemblyfacility, thereby permitting more rapid and consistent final assembly ofthe aircraft. Stated slightly differently, because the large structuresmay arrive just in time (approximately simultaneously) to the finalassembly facility, the final assembly facility may not have to wait aslong for all of the large structures to arrive, and may begin finalassembly sooner and/or more frequently than conventional aircraftmanufacturing approaches.

Additionally or alternatively, the actual manufacturing process of thepresent disclosure may be more efficient and/or faster than conventionalmanufacturing approaches that utilize third party suppliers. In someexamples of the present disclosure, aircraft components are fractionallypulsed down an assembly line such that multiple workstations may haveaccess to different portions of a component at the same time. Thisconfiguration permits the various workstations to perform work processes(e.g., different work processes) simultaneously on different areas of agiven component. In this way, work processes (e.g., different workprocesses) may be performed in parallel with one another, rather than inseries. Such parallel processing may increase production rates, andreduce the time needed to work on the components. In particular,increasing the workstation density on the assembly line enables morework to be performed on a component at any given time, thereby makingthe manufacturing process more efficient. Increasing the packing densityof the workstations also may reduce the total footprint (area) of themanufacturing system. That is, by breaking up the work processes intosmaller, more modular units, workstations, work-performing devices(e.g., machines, robots, tools, etc.), and constituent parts of theaircraft may be packed closer together, reducing the overall size of themanufacturing system.

Breaking a component down into multiple work areas also shrinks theeffective work areas, reducing the amount of tool, robot, machine,and/or human movement needed to complete the work processes, andtherefore reducing production inefficiencies. Thus, workers, tools,machines, and/or robots may not need to move as far to complete workprocesses (the work processes may be completed using smaller ranges ofmotion). Further, because the work areas may be smaller, the toolsand/or machines used by workers (also referred to herein asmanufacturing personnel) at these work areas may be made smaller and/orlighter, thereby increasing worker safety.

In addition to not having to move as far to complete the work processes,the tools, robots, machines, etc., may not have to complete as many workprocesses. For example, each tool, robot, and/or machine may only beresponsible for completing one work process. Thus, by breakingcomponents down into multiple work areas and/or by fractionally pulsingcomponents, the size, complexity, and cost of the tools, robots,machines, and/or other work-performing devices may be reduced. Statedslightly differently, the present disclosure provides smaller, simpler,and cheaper work-performing devices than conventional aircraftmanufacturing approaches.

Fractionally pulsing the components also may inhibit worker lethargy andencourage worker productivity because components move down the assemblyline more often and/or regularly than conventional pulsed assemblylines. Stated slightly differently, workers experience less idle timeand therefore may be less prone to boredom and/or listlessness. Further,the more frequent pulsing of a fractional line may increase workeraccountability because unfinished/incomplete work may be more visible toother workers and supervisors. In particular, incomplete work may holdup the line (i.e., interrupt/pause normal line movement), which, on afractional pulse line that pulses more frequently, may be morenoticeable/apparent, thereby ensuring that workers are held accountablefor their work.

FIGS. 1-6 illustrate systems and methods for manufacturing aircraftaccording to the present disclosure. FIGS. 1-3 provide examples ofaircraft manufacturing systems 10 according to the present disclosure,and/or components or portions thereof. In particular, FIG. 1schematically illustrates examples of aircraft manufacturing systems 10,and FIGS. 2-3 show examples of fractional pulse assembly lines 126 thatmay be included in aircraft manufacturing systems 10. Where appropriate,the reference numerals from the schematic illustration of FIG. 1 areused to designate corresponding parts of the examples of FIGS. 2-3 ;however, the examples of FIGS. 2-3 are non-exclusive and do not limitthe fractional pulse assembly lines 126 to the illustrated embodimentsof FIGS. 2-3 . That is, aircraft manufacturing systems 10 are notlimited to the specific embodiments of FIGS. 2-3 , and fractional pulseassembly lines 126 may incorporate any number of the various aspects,configurations, characteristics, properties, etc. of fractional pulseassembly lines that are illustrated in and discussed with reference tothe schematic representations of FIG. 1 and/or the embodiments of FIGS.2-3 , as well as variations thereof, without requiring the inclusion ofall such aspects, configurations, characteristics, properties, etc. Forthe purpose of brevity, each previously discussed component, part,portion, aspect, region, etc. or variants thereof may not be discussed,illustrated, and/or labeled again with respect to the examples of FIGS.2-3 ; however, it is within the scope of the present disclosure that thepreviously discussed features, variants, etc. may be utilized with theexamples of FIGS. 2-3 .

FIGS. 4-6 illustrate flowcharts schematically representing methods 500,600, and 700. Specifically, FIG. 4 illustrates methods 500 formanufacturing aircraft according to the present disclosure, FIG. 5illustrates methods 600 for operating a fractional pulse assembly lineof the present disclosure, and FIG. 6 illustrates methods 700 forforming a fractional pulse assembly line of the present disclosure.

As schematically illustrated in FIG. 1 , aircraft manufacturing systems10 are configured to produce aircraft 300. Aircraft 300 typicallyinclude at least a fuselage 302, wings 320, engine(s) 330, and a tail318. Fuselage 302 may include any number of discrete sections. In someexamples, fuselage 302 includes (e.g., may be broken down into) aforward fuselage section 304 positioned forward of wings 320, anintermediate fuselage section 310 (also referred to as wing fuselagesection 310 and/or intermediate main cabin portion 310) positionedbehind forward fuselage section 304 (e.g., where wings 320 tie into thefuselage), and an aft fuselage section 312 positioned behindintermediate fuselage section 310.

In some further such examples, forward fuselage section 304 includes anose portion 306 (also referred to as a cockpit portion 306) positionedat a front of the aircraft and a forward main cabin portion 308positioned behind the nose portion, between nose portion 306 andintermediate fuselage section 310. Additionally or alternatively, wingfuselage section 310 includes a wing box and an over-wing fuselageportion. The over-wing fuselage portion may be positioned above the wingbox, and together, the wing box and over-wing fuselage portion may forma complete (e.g., approximately cylindrical) section of the fuselage. Asan example, the over-wing fuselage portion may comprise a hemisphericalcylindrical portion (i.e., half barrel) of the intermediate fuselagesection. Additionally or alternatively, aft fuselage section 312includes an aft main cabin portion 314 and a tail portion 316 positionedbehind the aft main cabin portion. Thus, aft main cabin portion 314 maybe positioned between intermediate fuselage section 310 and tail portion316. Wings 320 include a left wing 322 and a right wing 324 configuredto be mirror images of one another and/or positioned on opposite sidesof fuselage 302.

In some examples, engines 330 include two engines, one coupled to eachof the wings (as depicted in the example of FIG. 1 ). In some examples,tail 318 includes one or more aerodynamic structures/surfaces such as avertical stabilizer (also referred to herein as tail fin) and/or ahorizontal stabilizer. Tail 318 also may be referred to herein asempennage 318 and/or tail assembly 318. The aforementioned components ofaircraft 300 are referred to collectively herein as section assemblies340 and/or aircraft large structures 340. Thus, section assemblies 340include the different portions of fuselage 302 (e.g., tail portion 316,aft main cabin portion 314, intermediate main cabin portion 310, forwardmain cabin portion 308, and nose portion 306), the wings, the tail, andthe engines.

Aircraft manufacturing systems 10 include manufacturing zones 12 thatare configured to produce constituent parts of aircraft 300 (e.g.,section assemblies, subassemblies, large structures, components,subcomponents, base parts, subassembly parts, and/or other parts ofaircraft 300), and/or the entire aircraft themselves. In some examples,a first manufacturing zone 20, a second manufacturing zone 40, and afourth manufacturing zone 80 when included, are configured to produceaircraft subassemblies which are then assembled at a third manufacturingzone 60 to produce aircraft assembly 78. In particular, firstmanufacturing zone 20, second manufacturing zone 40, and fourthmanufacturing zone 80 when included, are configured to produce a firstaircraft subassembly 38, a second aircraft subassembly 58, and a thirdaircraft subassembly 98, respectively, which are assembled together in athird manufacturing zone 60 to produce an aircraft assembly 78. Thus, inthe description herein, “subassembly” is used to describe constituentparts that are assembled together to produce aircraft assembly 78. Insome examples, one or more of the aircraft subassemblies (e.g., firstaircraft subassembly 38, second aircraft subassembly 58, third aircraftsubassembly 98, etc.) include and/or are the same as one or more of thelarge aircraft structures, as discussed previously. Thus, in some suchexamples, one or more of first manufacturing zone 20, secondmanufacturing zone 40 and fourth manufacturing zone 80 are configured toproduce section assemblies 340 and/or third manufacturing zone 60 isconfigured to produce aircraft 300. However, in other examples, none ofthe aircraft subassemblies include the large aircraft structures.

“Constituent part” is used generically herein to refer to any and allparts of aircraft 300. “Component” is used herein to refer to a firstorder constituent part of a given aircraft structure, and“sub-component” is used herein to refer to a second order constituentpart of a given aircraft structure (i.e., a component of a component).As an example, first aircraft subassembly 38 and/or second aircraftsubassembly 58 are components of aircraft assembly 78, and they in turninclude their own individual components that are sub-components ofaircraft assembly 78. Thus, “component” and “sub-component” are relativeterms that are used to refer to a given constituent part’s relationshipto the one or more larger structures within which it is included.“Constituent part” on the other hand, is used herein to refercollectively to any and all parts of a structure (e.g., any and allparts of aircraft assembly 78), regardless of how many orders ofsub-components and components separate the constituent part from thestructure.

Manufacturing zones 12 are distinguishable by their outputs (e.g., thesection assemblies, aircraft subassemblies, components, parts, etc.,manufactured, assembled, and/or otherwise produced by the manufacturingzones) and/or by the processes performed therein. That is, each of themanufacturing zones is configured to produce different outputs. Forexample, first manufacturing zone 20 is configured to manufacture,assemble, produce, and/or otherwise output first aircraft subassembly38, second manufacturing zone 40 is configured to manufacture, assemble,produce, and/or otherwise output second aircraft subassembly 58,different than the first aircraft subassembly 38, and thirdmanufacturing zone 60 is configured to manufacture, assemble, produce,and/or otherwise output aircraft assembly 78. Third manufacturing zone60 also is configured to receive the first aircraft subassembly fromfirst manufacturing zone 20 and the second aircraft subassembly fromsecond manufacturing zone 40, and to assemble the first aircraftsubassembly and the second aircraft subassembly to manufacture,assemble, produce, and/or otherwise output aircraft assembly 78.

In some examples, aircraft assembly 78 is aircraft 300, and thus, thirdmanufacturing zone 60 is configured to produce aircraft 300.Additionally or alternatively, first aircraft subassembly 38 and/or thesecond aircraft subassembly 58 is/are aircraft large structures 340(e.g., wings, one or more fuselage sections, tail, etc.), and thus,first manufacturing zone 20 and/or second manufacturing zone 40 is/areconfigured to produce section assemblies 340. In some such examples,first aircraft subassembly 38 includes wings 320 and second aircraftsubassembly 58 includes at least a portion of fuselage 302 (e.g., atleast forward main cabin portion 308 and aft main cabin portion 314),and thus, first manufacturing zone 20 is configured to produce wings 320and second manufacturing zone 40 is configured to produce at least aportion of fuselage 302, including one or more of forward main cabinportion 308, aft main cabin portion 314, nose portion 306, and/or tailportion 316. In some such examples, second manufacturing zone 40 isconfigured to produce forward main cabin portion 308 and aft main cabinportion 314.

When first manufacturing zone 20 is configured to produce wings 320, thefirst manufacturing zone may be configured to output the wings in theirfinal form and/or substantially in their final form. That is, the wingsmay only need small cosmetic changes (such as paint, detailing,coatings, curing, or other surface treatments) before being ready forflight and/or delivery to a customer. Thus, the wings may comprise allof their constituent parts when leaving first manufacturing zone 20.When second manufacturing zone 40 is configured to produce at least aportion of fuselage 302, the portions of fuselage 302 leaving secondmanufacturing zone 40 also may be flight ready and/or ready for finalassembly to produce aircraft 78, but may not be ready for customer use.As an example, the portions of fuselage 302 leaving second manufacturingzone 40 may not include interior features such as flooring, seating,lighting, and/or other customer-specific customizations.

In some examples, manufacturing zones 12 include additionalmanufacturing zones. As one such example, manufacturing zones 12 includefourth manufacturing zone 80 that is configured to produce thirdaircraft subassembly 98 that is different than first aircraftsubassembly 38 and second aircraft subassembly 58 and/or that is notconfigured to be produced by either first manufacturing zone 20 orsecond manufacturing zone 40. Thus, when included, fourth manufacturingzone 80 is configured to produce a subassembly that is different thanfirst aircraft subassembly 38 and second aircraft subassembly 58, but isnonetheless configured to be supplied to third manufacturing zone 60 andassembled to form aircraft assembly 78. As an example, fourthmanufacturing zone 80 is configured to produce one or more of wingfuselage section 310 (including a wing box and a top half/portion of thewing fuselage section), tail 318, nose portion 306 of fuselage 302, tailportion 316 of fuselage 302, landing gear, and/or engines. However insome examples, the engines and/or landing gear is/are not manufacturedby the manufacturing zone 40 and are delivered to the thirdmanufacturing zone 60 from one or more third party suppliers.

In some examples, tail portion 316 and/or nose portion 306 of fuselage302 are output to second manufacturing zone 40 before delivery to thethird manufacturing zone. Additionally or alternatively, wing fuselagesection 310 is output directly to third manufacturing zone 60.

Manufacturing zones 12 also may be referred to herein as productionzones, assembly zones, manufacturing regions, manufacturing locations,manufacturing facilities, manufacturing hangars, manufacturing wings,and/or manufacturing plants. As discussed above, the manufacturing zonesdiffer in the type(s) of aircraft components, aircraft subassemblies,assemblies, and/or other aircraft parts they are configured to produceand/or the type(s) of processes they are configured to perform.

In some examples, two or more of the manufacturing zones are physicallyseparated from (i.e., spaced away from) one another, but not so far thatthey are in different geographic regions (e.g., different cities,different counties, different states, different provinces, differentadministrative regions, different countries, and/or differentcontinents). As an example, first manufacturing zone 20 and secondmanufacturing zone 40 are physically separated from one another.Additionally or alternatively, third manufacturing zone 60 is physicallyseparated from first manufacturing zone 20 and/or second manufacturingzone 40. When included, fourth manufacturing zone 80 is physicallyseparated from the other manufacturing zones, in some examples. However,in other examples, fourth manufacturing zone 80 is not physicallyseparated from at least one of the manufacturing zones (e.g., thirdmanufacturing zone 60) and thus may be considered to overlap with or bewithin another manufacturing zone 12.

When two or more of the manufacturing zones are physically separatedfrom one another, they are physically separated from one another by atleast 1 meter (m), at least 5 m, at least 10 m, at least 20 m, at least30 m, at least 40 m, at least 50 m, at least 75 m, at least 100 m, atmost 3 kilometers (km), at most 2 km, at most 1 km, at most 0.75 km, atmost 0.5 km, at most 0.3 km, at most 0.2 km, at most 0.1 km, at most 75m, at most 50 m, and/or at most 25 m. As just one such example, firstmanufacturing zone 20 and second manufacturing zone 40 are physicallyseparated from one another by at least 5 m and at most 5 km.

Additionally or alternatively, two or more of manufacturing zones 12 arenot spaced away from another. As one such example, two or more ofmanufacturing zones 12 are adjacent to one another. As another example,two or more of manufacturing zones 12 overlap with one another. When twoor more of manufacturing zones 12 are not spaced away from one another,they may nevertheless be distinguished from one another by their outputsand/or work processes performed therein.

In some examples, manufacturing zones 12 include one or more buildings14 that define the physical bounds of manufacturing zones 12. Whenincluded, one or more buildings 14 include walls that define the limits(e.g., square footage) of manufacturing zones 12. Additionally oralternatively, one or more buildings 14 include ceilings, floors, etc.

In some examples, one or more buildings 14 include only one building andmanufacturing zones 12 are all included within the one building. In somesuch examples, the building includes wings, and two or more of themanufacturing zones are physically separated from one another indiscrete wings of the building, but nonetheless connected to one anotheras part of the one building. As one such example, first manufacturingzone 20 and second manufacturing zone 40 comprise different wings of thebuilding (and thus are physically separated from one another), but areconnected to one another by third manufacturing zone 60. As one suchexample, first manufacturing zone 20 and second manufacturing zone 40are joined to different parts of third manufacturing zone 60 to form twophysically distinct, but connected wings.

However, in other examples, one or more buildings 14 include more thanone building and two or more of the manufacturing zones are included indifferent buildings. That is, two or more of the manufacturing zones areincluded in their own discrete buildings that are physically separatedfrom one another and are not physically connected by walls or otherbuilding structures. As an example, first manufacturing zone 20 isincluded in a first building, and second manufacturing zone 40 isincluded in a second building. In some such examples, firstmanufacturing zone 20 and/or second manufacturing zone 40 is/arephysically separated from third manufacturing zone 60, and thus theoutputs of first manufacturing zone 20 and/or second manufacturing zone40 are transported between first manufacturing zone 20 and/or secondmanufacturing zone 40 and third manufacturing zone 60, over adistance/gap separating first manufacturing zone 20 and/or secondmanufacturing zone 40 from third manufacturing zone 60.

Thus, in some examples, such as where two of more of manufacturing zones12 are physically separated from one another in different buildings,aircraft manufacturing systems 10 include one or more transportationdevices 100 that are configured to transport components, sub-components,assemblies, aircraft subassemblies and/or other aircraft parts to, from,and/or between one or more of the manufacturing zones. In some examples,a transportation device 100 includes one or more of a hoist mechanism102, a conveyor system 104, and/or a shuttle 106. Hoist mechanisms 102are configured to lift aircraft constituent parts. As examples, a hoistmechanism 102 may include a crane and/or a pulley system. In someexamples, a hoist mechanism 102 is configured to rotate, pivot,translate, and/or otherwise move about a fixed point. Conveyor systems104 include any suitable conveyor, such as a roller conveyor, beltconveyor, chain conveyor, etc. Shuttles 106 may include a motorizedland, water, and/or aerial vehicle that is configured to travel to,from, between, and/or around one or more of the manufacturing zones totransport constituent parts. As examples, shuttles 106 may include oneor more of a barge, cargo ship, truck, bus, van, tractor, train, drone,and/or helicopter.

In one example, a first transportation device 110 is configured totransport constituent parts between first manufacturing zone 20 andthird manufacturing zone 60. As an example, first transportation device110 includes a crane that is configured to transport first aircraftsubassembly 38 from first manufacturing zone 20 to third manufacturingzone 60. In some such examples, the crane is a gantry crane or othertype of elevated rolling mechanism. Additionally or alternatively,transportation devices 100 may include a second transportation device112 that is configured to transport constituent parts between secondmanufacturing zone 40 and third manufacturing zone 60. When fourthmanufacturing zone 80 is included, transportation devices 100additionally or alternatively may include a third transportation device114 that is configured to transport constituent parts between fourthmanufacturing zone 80 and third manufacturing zone 60 and/or a fourthtransportation device 116 that is configured to transport constituentparts between fourth manufacturing zone 80 and second manufacturing zone40. As an example, fourth transportation device 116 includes a conveyorsystem and/or a gantry crane or other movable hoist mechanism that isconfigured to transport parts of aircraft 300 from fourth manufacturingzone 80 to second manufacturing zone 40.

In some examples, third transportation device 114 is configured totransport intermediate fuselage section 310 (including the wing boxand/or upper half/portion of the intermediate fuselage section) fromfourth manufacturing zone 80 to third manufacturing zone 60.

In some examples, fourth transportation device 116 is configured totransfer at least a portion of fuselage 302 from fourth manufacturingzone 80 to second manufacturing zone 40. In some such examples, fourthtransportation device 116 is configured to transfer nose portion 306and/or tail portion 316 of fuselage 302 from fourth manufacturing zone80 to second manufacturing zone 40.

Manufacturing zones 12 additionally or alternatively include one or moredoorways 16 that are configured to permit entry and/or exit ofconstituent parts 200 into and/or out of manufacturing zones 12. One ormore doorways 16 also may be referred to or described as gates, portals,entrances, exits, throughways, transfer locations, ingresses, and/oregresses. In some examples, one or more buildings 14 include the one ormore doorways. Constituent parts 200 include base parts 202 andsubassembly parts 204. In some examples, one or more doorways 16 areconfigured to receive base parts 202. Base parts 202 are constituentparts that are manufactured or otherwise procured from outside ofaircraft manufacturing systems 10 (and thus may include one or more ofraw materials, prefabricated parts, fasteners, tools, etc.) and that arebrought into the manufacturing zones by the transportation devices.Thus, work processes in the manufacturing zones begin by adding to,subtracting from, and/or otherwise modifying the base parts; the baseparts are the elementary constituent parts (e.g., the inputs) to themanufacturing zones. Subassembly parts 204 are an assembly of two ormore base parts 202 that are assembled on one or more of the feederlines and that are introduced to one or more of the assembly lines viathe one or more of the feeder lines. In some such examples, thirdmanufacturing zone 60 includes one or more doorways 16 that areconfigured to receive one or more of first aircraft subassembly 38,second aircraft subassembly 58, and/or third aircraft subassembly 98.

Subassembly parts 204 may include precursors 206 to one or more of theaircraft subassemblies, also referred to herein as aircraft subassemblyprecursors 206. The aircraft subassembly precursors comprise thestructures on assembly lines 120 that advance along assembly lines 120and eventually become the outputs of the manufacturing zones, once thework processes in the manufacturing zones are completed. For example,the precursors may be the structures to which constituent parts fromfeeder lines 140 are added. Thus, the aircraft subassembly precursorsmay be the structures on the main stem of the assembly lines 120 (thecommon assembly line that eventually produces the final output of themanufacturing zone in which it is included) that advance towards the endof the assembly lines 120 and become the final output of themanufacturing zones. For example, the precursor of the firstmanufacturing zone may be a wing precursor. The wing precursor advancesalong the assembly line of the first manufacturing zone and may takedifferent shapes, structures, and/or properties as it advances along theassembly line and is added to, subtracted from, changed, processed,and/or otherwise worked on. Thus, precursors 206 are illustrated in FIG.1 with dash-dot lines to reflect the fact that the shape, size,structure, composition, characteristics, and/or other properties of theprecursors may change as the precursors travel down assembly lines 120.The precursor may eventually be transformed to the final output (i.e. itmay eventually become a completed left-side wing or right-side wing)once all of the work processes in the first manufacturing zone have beenperformed on the precursor. Thus, the precursor is just an incompleteand/or partial version of a final output of the manufacturing zones.

In some such examples, the manufacturing zones include a sufficientnumber of the doorways such that each of the one or more doorways isconfigured to receive a unique constituent part and/or a unique set ofconstituent parts. That is, different constituent parts may be deliveredto different doorways. Thus, including more doorways along themanufacturing zones enables constituent parts to be delivered closer totheir point of consumption, assembly, and/or use in the manufacturingzones. Further, delivering parts to their final destinations from aplurality of origins (e.g., doorways) streamlines the delivery process,reduces congestion, and mitigates bottlenecks in the delivery process.In this way, constituent parts may be delivered to their finaldestination in a more efficient manner than conventional deliveryapproaches that deliver parts to various places in a manufacturing zonefrom a single source/origin (e.g., doorway).

Additionally or alternatively, one or more doorways 16 are configured toreceive and/or convey constituent parts 200 between manufacturing zones12. As an example, fourth manufacturing zone 80 and second manufacturingzone 40 include one or more doorways 16 that are configured to permitconstituent parts 200 to be transferred from fourth manufacturing zone80 to second manufacturing zone 40. As discussed above, in some suchexamples, transportation device 100 also is included between fourthmanufacturing zone 80 and second manufacturing zone 40, and isconfigured to transport the constituent part between fourthmanufacturing zone 80 and second manufacturing zone 40. As an example,transportation device 100 is configured to transfer at least a portionof fuselage 302 from fourth manufacturing zone 80 to secondmanufacturing zone 40. As one such example, transportation device 100 isconfigured to transfer nose portion 306 and/or tail portion 316 offuselage 302 from fourth manufacturing zone 80 to second manufacturingzone 40.Additionally or alternatively, one or more doorways 16 areconfigured to discharge the outputs of manufacturing zones 12 from themanufacturing zones. As an example, one or more of first manufacturingzone 20 includes one or more doorways 16 that is/are configured todischarge first aircraft subassembly 38, second manufacturing zone 40includes one or more doorways 16 that is/are configured to dischargesecond aircraft subassembly 58, third manufacturing zone 60 includes oneor more doorways 16 that is/are configured to discharge aircraftassembly 78, and/or fourth manufacturing zone 80 includes one or moredoorways 16 that is/are configured to discharge third aircraftsubassembly 98. As an example, one or more of the doorways is/areconfigured to discharge nose portion 306 and/or tail portion 316 offuselage 302 to second manufacturing zone 40 and/or one or moredifferent doorways is/are configured to discharge wing fuselage section310 to third manufacturing zone 60.

In some examples, base parts 202 are delivered to manufacturing zones 12via pathways 18. When included, pathways 18 are configured to permitdelivery of base parts 202 to manufacturing zones 12 from outside ofaircraft manufacturing systems 10 or at least from outside of amanufacturing zone 12 thereof. As an example, pathways 18 are configuredto permit travel of transportation devices 100, which in turn areconfigured to carry base parts 202 of aircraft assembly 78. In someexamples, pathways 18 extend around at least a portion of manufacturingzones 12. In particular, pathways 18 are configured to permit the travelof transportation devices 100 around at least a portion of themanufacturing zones. In such examples, pathways 18 extend around atleast a portion of a perimeter of one or more of first manufacturingzone 20, second manufacturing zone 40, third manufacturing zone 60,and/or fourth manufacturing zone 80. In some such examples, pathways 18extend to one or more doorways 16 and permit transportation devices 100to travel directly to one or more doorways 16, and therefore deliverconstituent parts 200 directly to the one or more doorways. As anexample, when transportation devices 100 include land-based vehicles,(e.g., trucks, vans, buses, shuttles, trains, etc.) pathways 18 includeroads or other suitable surfaces that are configured to permit travel ofthese land-based vehicles. In some examples, pathways 18 are configuredto be one-way pathways that limit travel of the transportation devices100 to one direction.

In some examples, one or more of manufacturing zones 12 include assemblylines 120. When included, assembly lines 120 include a series ofworkstations that are configured to perform work on constituent parts200 of the aircraft assembly 78. Assembly lines 120 are configured toguide constituent parts 200 through the series of workstations along aone-way path that constitutes at least a portion of one or more ofmanufacturing zones 12. In this way, work is performed on theconstituent parts at various locations (e.g., workstations) on assemblylines 120.

In some examples, assembly lines 120 include a drive mechanism 122(e.g., electric motor) that is configured to propel the constituentparts down assembly lines 120. In some such examples, drive mechanism122 is configured to propel a mechanical linkage 124 (e.g., one or moreof belt, chain, pulley, cable, and/or platform) that is configured tomaintain contact with one or more of the constituent parts (e.g., viafrictional forces and/or magnetic forces) as it moves, and thus propelthe constituent parts through at least a portion of manufacturing zones12. In some further such examples, assembly lines 120 include a conveyorsystem driven by drive mechanism 122, such as one or more of a beltconveyer system, roller conveyor, belt conveyor, chain conveyor, cableconveyor, etc. However, in other examples, drive mechanism 122 includesa motorized vehicle such as an aircraft tug.

Assembly lines 120 include one or more of a first assembly line 130, asecond assembly line 132, and a third assembly line 134, in someexamples. When included, first assembly line 130 is included in firstmanufacturing zone 20 and is configured to propel constituent parts 200of first aircraft subassembly 38 and/or first aircraft subassembly 38through at least a portion of first manufacturing zone 20. Whenincluded, second assembly line 132 is included in second manufacturingzone 40 and is configured to propel constituent parts 200 of secondaircraft subassembly 58 and/or second aircraft subassembly 58 through atleast a portion of second manufacturing zone 40. When included, thirdassembly line 134 is included in third manufacturing zone 60 and isconfigured to propel constituent parts 200 of aircraft assembly 78and/or aircraft assembly 78 through at least a portion of thirdmanufacturing zone 60. Although three assembly lines 120 are illustratedin FIG. 1 (one in each of the first, second, and third manufacturingzones), it should be appreciated that, in other examples, each of themanufacturing zones may include more or less than one assembly line 120.Further, each assembly line 120 may include one or more subassemblylines. For examples, one or more of the assembly lines may include oneor more main assembly lines and one or more tributary assembly lines(e.g., feeder lines 140) that branch off from larger, main assemblylines. The assembly lines 120 may branch into increasingly smallersubassembly lines, in some examples. Thus, each of the assembly linesmay include a network of tributary assembly lines that eventually feedinto a common assembly line. In this way, assembly lines 120 may branchoff into one or more subassembly lines and/or may join together to formone or more common assembly lines.

In some examples, when included, fourth manufacturing zone 80 does notinclude assembly lines 120. However, in other examples, fourthmanufacturing zone 80 does include one or more assembly lines 120.Regardless, fourth manufacturing zone 80 includes stationary bays 84(also referred to herein as parking spaces 84 and/or hangars 84) thatare configured to perform multiple work processes, one at a time (i.e.,in series), on constituent parts 200. Stationary bays 84 are configuredto hold constituent parts 200 for a longer duration than workstations ofassembly lines 120. In some examples, different stationary bays 84 areconfigured to manufacture different parts. As an example, one ofstationary bays 84 is configured to manufacture at least a portion ofwing fuselage section 310,another one of stationary bays 84 isconfigured to manufacture tail portion 316 of fuselage 302, and anotherone of stationary bays 84 is configured to manufacture nose portion 306of fuselage 302. In some examples, stationary bays 84 are configured toproduce third aircraft subassembly 98.

Manufacturing zones 12 additionally include feeder lines 140, in someexamples. When included, feeder lines 140 are configured to introducebase parts 202 and/or subassembly parts 204 to assembly lines 120. As anexample, feeder lines 140 are configured to transfer base parts 202and/or subassembly parts 204 from doorways 16 to assembly lines 120. Inparticular, feeder lines 140 may join with one or more of the assemblylines to deliver base parts 202 and/or subassembly parts 204 thereto. Insome examples, assembly lines 120 include feeder lines 140. In suchexamples, feeder lines 140 may be subassembly lines (also referred toherein as tributary assembly lines) of assembly lines 120. In otherexamples, feeder lines 140 may be separate and distinct from assemblylines 120. As with assembly lines 120, feeder lines 140 may include oneor more sub-feeder lines that branch off one or more main feeder lines.That is the feeder lines may include a network of tributary feeder linesthat eventually feed into a main feeder line.

Additionally or alternatively, the feeder lines are configured to orientthe base parts and/or subassembly parts in a final orientation. Thefinal orientation is the orientation in which the base parts and/orsubassembly parts are coupled to the structure (e.g., aircraftsubassembly precursor 206) on the assembly line. In some examples,doorways 16 are configured to receive the parts in their finalorientation. Additionally or alternatively, the feeder lines themselvesare configured to orient the parts in their final orientation after theparts have been loaded onto the feeder lines. Thus, the orientation ofthe base parts and/or subassembly parts may not need to be rotated,pivoted, or otherwise changed by the robots, machines, and/or workerswhen assembling or coupling the base parts and/or subassembly parts tothe larger aircraft structure (e.g., aircraft subassembly precursor 206)on the assembly line. Thus, by providing the base parts and/orsubassembly parts to the feeder lines and/or the assembly lines in theirfinal orientation, production inefficiencies within the manufacturingzones may be reduced.

In some examples, the feeder lines include fractional pulse assemblylines that are configured to fractionally pulse base parts 202 and/orsubassembly parts 204 to assembly lines 120. As an example, the feederlines include fractional pulse assembly lines 126.

Additionally or alternatively, the feeder lines include more than onefractional pulse assembly line and/or include a main feeder line and oneor more sub-feeder lines that are configured to deliver constituentparts to the main feeder line. In this way, the feeder lines may branchinto increasingly smaller upstream feeder lines. Thus, the manufacturingzones 12 may each include one or more of the assembly lines, and each ofthe assembly lines may branch into increasingly smaller feeder lines. Inthis way, the manufacturing zones 12 may include a network of tributaryassembly lines that eventually all feed into third manufacturing zone60.

In some examples, base parts 202 are delivered to manufacturing zones 12by transportation devices 100 via pathways 18, enter manufacturing zones12 via doorways 16, and then are ferried to assembly lines 120 viafeeder lines 140. In some examples, feeder lines 140 include the same orsimilar devices of assembly lines 120 (e.g., conveyor systems). In someexamples, the subassembly parts 204 are manufactured on the feeder lines140 and/or are a product/output of the feeder lines 140. In suchexamples, the transportation devices 100 may deliver base parts 202 tothe feeder lines 140, and the subassembly parts may be manufactured onthe feeder lines from these base parts.

By including the pathways, the one or more doorways, and/or the feederlines, constituent parts may be delivered closer to their point ofassembly on the assembly lines. Further, feeding constituent parts tothe assembly lines from a plurality of feeder lines, as opposed to acommon dock, reduces queue wait times and/or other constituent partdelivery inefficiencies, thereby increasing production rates.

In some examples, different doorways are configured to receiveconstituent parts in the order in which they are assembled on theassembly line. As an example, a first door may receive a firstconstituent part and an adjacent second door may receive a secondconstituent part that is configured to be assembled directly after thefirst constituent part. For example, fuselage frames may be installedbefore windows and/or window frames on a fuselage skin, and thus, thefuselage frames may be delivered to a different doorway than the windowsand/or window frames. Further, the fuselage frames may be fed to a moreupstream position of the assembly line than the windows and/or windowframes via one of the feeder lines.

In some examples, assembly lines 120 include fractional pulse assemblylines 126. When included, fractional pulse assembly lines 126 areconfigured to pulse (i.e., periodically move) constituent parts by onlya fraction of a length of the constituent parts 200 (i.e., by less thanthe length of the constituent parts 200) in the direction of movement.Thus, unlike conventional pulsed assembly lines in which constituentparts 200 are pulsed to an entirely different, non-overlapping locationwhere a new workstation is located (e.g., pulsed by more than theirlength), fractional pulse assembly lines 126 micro-pulse the constituentparts to an overlapping position that still includes at least one ormore of the workstations from the previous position. Further, unlikeconventional pulsed assembly lines in which work is performed on a givenconstituent part by one workstation at a time (i.e., differentworkstations perform work on a constituent part serially), multipleworkstations of fractional pulse assembly lines 126 are configured toperform work on the constituent parts in parallel (i.e.,simultaneously). Because fractional pulse assembly lines 126 pulseconstituent parts 200 by less than their length, a given workstationserially performs work on different sections of a given constituent partsince the constituent part is fractionally pulsed past the workstationin multiple pulses. That is, unlike conventional pulsed assembly linesin which a constituent part enters a workstation on a first pulse andexits the workstation on an immediately next, second pulse, fractionalpulse assembly lines 126 of the present disclosure utilize more than twopulses for a constituent part to both enter and exit the workstation.

In some examples, two or more of first manufacturing zone 20, secondmanufacturing zone 40, and fourth manufacturing zone 80 when included,produce first aircraft subassembly 38, second aircraft subassembly 58,and third aircraft subassembly 98, respectively, at least atsubstantially the same rate (e.g., production times for the aircraftsubassemblies are within 5% of one another), such that the aircraftsubassemblies are provided to third manufacturing zone 60 atapproximately the same time (i.e., just in time). In some such examples,base parts 202 are provided to first manufacturing zone 20, secondmanufacturing zone 40, and fourth manufacturing zone 80 when included,at approximately the same time. In some further such examples, wherefirst manufacturing zone 20 and second manufacturing zone 40 includeassembly lines of substantially the same length (e.g., within 5% of thelength of one another) the average velocity of the assembly lines issubstantially the same (e.g., within 5% of one another).

Turning to FIGS. 2-3 , they illustrate example fractional pulse assemblylines 400 of fractional pulse assembly lines 126. Fractional pulseassembly lines 126 may be included in assembly lines 120, feeder lines140, and/or other assembly lines of aircraft manufacturing systems 10.The fractional pulse assembly lines 126 include workstations that areconfigured to perform work on constituent parts pulsed by the fractionalpulse assembly lines. Further, the workstations may include a poweredmechanism (e.g., conveyor system) that is configured to move (e.g.,fractionally pulse) the constituent parts along the assembly lines. Thedistance between the centerlines of adjacent workstations on thefractional pulse assembly lines may be referred to herein as theworkstation pitch. The number of workstations per unit length on theassembly line may be referred to as the workstation density orworkstation packing density.

FIG. 2 provides graphs comparing fractional pulse assembly lines 126 ofthe present disclosure to conventional pulsed assembly lines. Inparticular, graph 450 shows an example conventional pulsed assembly line440, while graphs 452 and 454 show example fractional pulse assemblylines 400 according to the present disclosure. Unlike conventionalpulsed assembly line 440 in which constituent parts 200 are pulsed bymore than their length between workstations 410, constituent parts 200of the present disclosure are pulsed by less than their length betweenworkstations 410. In particular, in conventional pulsed assembly line440, constituent parts 200 are pulsed from a first workstation 412 to asecond workstation 414, whereas in fractional pulse assembly lines 126of the present disclosure, constituent part 200 is pulsed by less thanits length from first workstation 412 to second workstation 414. Thus,the workstations are smaller and/or closer together in the presentdisclosure than in conventional pulsed assembly line 440 for comparablysized constituent parts. Stated slightly differently, the assembly linesof the present disclosure have a higher workstation packing density thanconventional assembly lines. In this way, more work may be performed ona part at any given time because more workstations may have access tothe part at any given time. Further, because the workstations may bepacked more densely together, the total footprint (area) of themanufacturing system may be reduced. Graph 452 illustrates an examplewhere one of constituent parts 200 is pulsed by one third of its lengthduring each pulse, and graph 454 illustrates an example where one ofconstituent parts 200 is pulsed by one ninth of its length during eachpulse.

As illustrated, the workstations become smaller and/or closer together(i.e., the pitch of the workstations decreases) as the pulse length(e.g., the distance constituent parts 200 move during a pulse) isshortened. Additionally or alternatively, a pulse frequency increaseswhen the pulse length decreases. That is, there is less time betweenpulses when the pulse length is shortened because more pulses are neededto propel the constituent parts 200 the same distance. As illustrated inthe example of FIG. 2 , constituent parts 200 in graph 454 are pulsedmore frequently than constituent parts 200 in graph 452 sinceconstituent parts in graph 452 are pulsed farther than in graph 454.Shorter pulse lengths and smaller workstations enable more workstationsto simultaneously perform work on constituent parts 200 (i.e., theworkstation packing density is increased). Increasing the amount ofparallel processing of constituent parts 200 in this way increasesproduction efficiencies and reduces production times. The minimum sizeof the workstations is limited by a variety of factors including one ormore of a uniformity of constituent parts 200 along a length of theconstituent parts, an amount of similarity in the work process to beperformed on the constituent parts along the length of the constituentpart, an order of the work processes, a delay between work processes,and/or a size of the machines, robots, tools, and/or workers needed toperform the work processes at the workstations.

In some examples, first workstation 412 and second workstation 414perform different work processes on constituent parts 200. Additionallyor alternatively, different tools, robots, and/or workers perform workon constituent parts 200 at first workstation 412 and second workstation414. A work process includes one or more of adding to (e.g., couplingtwo or more base parts 202 together, coupling a subassembly part 204 toa base part 202, coupling a base part 202 and/or a subassembly part 204to one of aircraft subassembly precursors 206, coupling two or moresubassembly parts 204 together, etc.), subtracting from (e.g., drillingholes in), and/or otherwise modifying (e.g., re-forming, re-shaping,bending, curing, sterilizing, treating, heating, cooling, pressurizing,etc.) constituent parts 200. Thus, performing a work process includesperforming work on one or more of constituent parts 200.

As illustrated in FIG. 3 , workstations 410 (also referred to herein asassembly line workstations 410) each include a work-performing device420 that is configured to perform the work processes (i.e., to performwork on constituent parts 200). As examples, work-performing device 420includes one or more of a robot 422, a machine 424, a human worker 426,and/or a tool 428. Robot 422 is an autonomous device that is configuredto perform work without human input and/or intervention. Machine 424 isa relatively large device that is configured to perform work based onhuman input. As examples, machine 424 may be a machine tool, such as apress, a mill, a lathe, etc. Tool 428 is smaller than machine 424 and isconfigured to perform work based on human input. As an example, tool 428may be a hand-held device.

In some examples, two or more of the workstations perform different workprocesses on constituent parts 200. In some such examples, each of theworkstations performs a unique type of work process on the constituentparts, such that all of the workstations perform different workprocesses on the constituent parts. Additionally or alternatively, insome examples, each of the workstations performs only one type of workprocess on the constituent parts (e.g., only drilling holes, onlycutting out windows, only installing frames, only installing stringers,only installing sealant, etc.). Thus, in such examples, each workstationperforms only one type of work process that is unique to that particularworkstation.

Additionally or alternatively, in some examples, two or more of theworkstations include different types of work-performing devices 420 thatare configured to perform different types of work processes. In somesuch examples, each of the workstations includes a unique type ofwork-performing devices 420 and/or a unique combination ofwork-performing devices 420, such that all of the workstations areconfigured to perform different types of work processes. In some suchexamples, each workstation only includes one work-performing device 420and/or one type of work-performing device.

As an example, a portion of a fractional pulse assembly line includes atleast seven workstations located at various serial positions along theassembly line that perform their own unique work process. In some suchexamples, the at least seven workstations are divided into a first setof workstations that installs fuselage frames and a second set ofworkstations, positioned downstream of the first set of workstations,that installs window frames. Thus, in such examples, the fuselage framesare installed first, and then the window frames. The fuselage frames maybe installed first to increase the structural integrity of the fuselageskin prior to window installation. In some such examples, installing thefuselage frames and the window frames includes drilling holes forfasteners, laying up the window frames and/or fuselage frames withtemporary fasteners, and then installing the fasteners.

As examples, the most upstream workstation of the first set ofworkstations (the fuselage frame installing workstations) drills holeson the skin for the fuselage frame fasteners, the next workstation (theadjacently positioned downstream workstation) lays up the fuselage frameon the skin with temporary fasteners, and then a third workstationinstalls the permanent fasteners. Two of the most upstream workstationsof the second set of workstations (the window frame installingworkstations) drill holes in the fuselage skin for the window framefasteners and cut out the window openings in the skin. Downstreamworkstations of the second set of workstations lay up the window frameswith temporary fasteners and then install the permanent fasteners in thewindow frames.

In this way, each workstation 410 and/or each work-performing device 420may perform the same work process over and over again on the varioussections of the constituent parts. That is, by breaking the constituentparts down into sections and configuring the workstations to onlyperform work on one section at a time, each workstation and/orwork-performing device may be simplified such that the workstationand/or work-performing device repeatedly performs the same work and/oronly performs one type of work. Not only may the workstations and/orwork-performing devices be configured to perform the same type of work,but the workstations and/or work-performing devices also may beconfigured to perform the same type of work on the same location of eachsection of the constituent parts. As an example, a given workstationthat is configured to drill holes in a fuselage skin also may beconfigured to drill these holes in the same position on each section ofthe fuselage skin (i.e., all of the sections may include the same numberof holes, the same positioning of the holes, and/or same holeconfiguration/pattern). Thus, the work-performing device may not need tomove at all and/or may move in the same manner after each pulse whendrilling the holes in the different sections of the fuselage skin as thesections are fractionally pulsed past the workstation. In this way, thework-performing devices themselves and/or the programming thereof may besimplified as compared to conventional assembly lines approaches.

In this way, by performing only one type of work process, the size,complexity, and/or cost of the work-performing devices may be reduced ascompared to conventional work-performing devices that are configured toperform multiple types of work processes. Further, by fractionallypulsing the constituent parts and dividing the work processes intosmaller work areas, the amount of movement needed to perform the workprocesses may be reduced, thereby further reducing the size, complexity,and cost of the work-performing devices.

In the example of FIG. 3 , six workstations 410 are illustrated.However, in other examples, more or less than six workstations 410 areincluded in example fractional pulse assembly lines 400. Althoughworkstations 410 are only illustrated along one side of the components,the workstations may be positioned along both sides of the components.Further, the example fractional pulse assembly line shown in FIG. 3 isonly a portion of fractional pulse assembly lines 126, in some examples.In some such examples, fractional pulse assembly lines 126 include twoor more of example fractional pulse assembly lines 400.

In some examples, fractional pulse assembly lines 400 include anassembly area 430 where sub-components 404 are configured to beassembled to form components 406. Additionally or alternatively,components 406 enter a queue 434 where work is not configured to beperformed on the components. Components 406 are fractionally pulsedthrough the workstations, and work is performed on the components byeach work-performing device 420. In some examples, subassembly parts 204and/or base parts 202 are added to components 406 at one or more ofworkstations 410. After exiting workstations 410, components 406 enteranother assembly area 430, in some examples, and are assembled togetherto become sub-components of a new component.

In some examples, constituent parts 200 having different physicalproperties are pulsed down the same fractional pulse assembly line,and/or workstations 410 perform work on constituent parts 200 havingdifferent physical properties, such as one or more of shape, geometry,size, weight, surface features, etc. As an example, components 406include a first component 407 and a second component 408 comprisingdifferent physical properties. As one such example, first component 407is longer than second component 408, as illustrated in FIG. 3 . Thus, insuch examples, constituent parts of different lengths are pulsed downthe same fractional pulse assembly line.

Additionally or alternatively, FIG. 3 illustrates how workstations 410are not all the same length, in some examples. In some such examples,the lengths of workstations 410 are multiples of another. For example,in FIG. 3 , the longer workstation is twice the length of the otherworkstations. However, in other examples, the lengths of workstations410 are not exact integer multiples (e.g., twice, three times, fourtimes, etc.) of the lengths of other workstations. In some examples,constituent parts 200 are pulsed by an amount equal to the shortestworkstation of workstations 410 (i.e., a minimum workstation length).

A pulse length 460 is a distance travelled by constituent parts 402during a pulse. As discussed above, the pulse length in fractional pulseassembly lines 126 of the present disclosure is less than a length ofthe constituent parts. Thus, in the example of FIG. 3 , the pulse lengthis equal to one third of the length of first component 407 and one halfof the length of second component 408. A work period 464 is the durationbetween pulses, during which constituent parts 402 are stationary and/orwork is configured to be performed on constituent parts 402. In otherwords, work period 464 is the duration between the end of a pulse andthe beginning of a subsequent pulse. A pulse duration 466 is the time ittakes to complete a pulse, that is, to move constituent parts 402 theentire pulse length to a new position on fractional pulse assembly lines126. A pulse period 462 is equal to a full fractional pulse cycle: thework period plus the pulse duration.

In some examples, a length of the constituent parts is an integermultiple of the pulse length. As examples, constituent parts 200 aretwo, three, four, five, six, seven, eight, nine, ten, eleven, twelve,thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen,and/or twenty times the length of the pulse length. Thus, in suchexamples, the pulse length is equal to 1/X of the length of constituentparts 200, where X is an integer value. As discussed above, in some suchexamples, the pulse length is equal to the length of the shortestworkstation(s) of workstations 410 (i.e., a minimum workstation length),and thus, the shortest workstation(s) of workstations 410 also is equalto 1/X of the length of constituent parts 200, where X is an integervalue.

In some examples, a given work process (e.g., drilling holes) may beperformed in the same manner at regular intervals along the length ofthe constituent part. For example, Y number of vertically aligned holes(e.g., five holes) may be drilled in an aircraft skin every X meters(e.g., every 1 m). Thus, in some such examples, the five holes may bedrilled in the aircraft skin at one meter intervals. In some furthersuch examples, the regular intervals of a given work process may beequal to the pulse length. Thus, in the above example, the pulse lengthmay be one meter, such that the work-performing device does not have tomove to drill holes on the next section of the constituent part. In someexamples, the workstations on a fractional pulse assembly line arechosen based on the regular intervals of the work processes theyperform. In some examples, workstations may be selected that have thesame regular intervals, and/or integer multiples thereof, so that thepulse length does not have to be changed and/or so that thework-performing devices do not have to move laterally as much betweenpulses to perform the work process on different sections.

As an example, a constituent part may be configured to include windowsevery X meter, frames every X meter, and a column of vertical holesevery X/Y meter. A first workstation may be configured to cut out thewindow opening, a second workstation may be configured to install theframes, and a third workstation may be configured to drill the holes. Insome such examples where X = 1 meter, Y = 2 meters and the pulse length= 0.5 meters, the third workstation performs its work process (drills avertical column of holes) after every pulse. However, the first andsecond workstations only perform their work processes after every secondpulse (every other pulse), since their work processes only need to beperformed at 1 meter intervals (equal to two pulse lengths). In anothersuch example where X = 1 meter and Y = 2 meters, but where the pulselength = 1 meter, the third workstation must drill two columns ofvertical holes after each pulse, and the first and second workstationperform their work processes (cut out a window opening and install aframe) once after each pulse.

However, in other examples, X is not an integer value and the length ofconstituent parts 200 is not equal to an integer multiple of the pulselength.

FIGS. 4-6 schematically provide flowcharts that represent illustrative,non-exclusive examples of methods according to the present disclosure.In FIGS. 4-6 , some steps are illustrated in dashed boxes indicatingthat such steps may be optional or may correspond to an optional versionof a method according to the present disclosure. That said, not allmethods according to the present disclosure are required to include thesteps illustrated in solid boxes. The methods and steps illustrated inFIGS. 4-6 are not limiting and other methods and steps are within thescope of the present disclosure, including methods having greater thanor fewer than the number of steps illustrated, as understood from thediscussions herein. Further steps from different methods and/ordifferent figures may be combined.

FIGS. 4-6 illustrate example methods according the present disclosure.In particular, FIG. 4 illustrates methods 500 for manufacturing aircraftassemblies (e.g., aircraft assembly 78), such as aircraft (e.g.,aircraft 300), according to the present disclosure, FIG. 5 illustratesmethods 600 for fractionally pulsing constituent parts (e.g.,constituent parts 200) down a fractional pulse assembly line (e.g.,fractional pulse assembly lines 126), and FIG. 6 illustrates methods 700for designing and/or constructing aircraft manufacturing systems (e.g.,aircraft manufacturing systems 10) of the present disclosure. With thisscope of the present disclosure are methods that include steps from morethan one of methods 500, methods 600, and/or methods 700, as understoodfrom the discussions herein.

Methods 500 include manufacturing (or assembling) aircraft subassemblies(e.g., first aircraft subassembly 38, second aircraft subassembly 58,and/or third aircraft subassembly 98) in parallel in the same geographicregion and/or on separate assembly lines (e.g., assembly lines 120) at502. For example, the manufacturing at 502 may comprise sending one ormore of the first aircraft subassemblies 38 and constituent parts 200thereof down a first assembly line 130 and sending one or more of thesecond aircraft subassemblies 58 and constituent parts 200 thereof downa second assembly line 132, which assembly lines may be fractional pulseassembly lines, as discussed herein. As discussed above, manufacturingin the same geographic region comprises manufacturing the aircraftsubassemblies in manufacturing zones (e.g., manufacturing zones 12) thatare separated by at most 3 km, at most 2 km, at most 1 km, at most 0.75km at most 0.5 km, at most 0.3 km, at most 0.2 km, at most 0.1 km, atmost 75 m, at most 50 m, and/or at most 25 m. Thus, in such examples,manufacturing at 502 includes manufacturing the aircraft subassembliesin different manufacturing zones. As one such example, the manufacturingincludes manufacturing the first aircraft subassembly in a firstmanufacturing zone (e.g., first manufacturing zone 20) and manufacturingthe second aircraft subassembly in a second manufacturing zone (e.g.,second manufacturing zone 40). In some examples, manufacturing theaircraft subassemblies on separate assembly lines comprisesmanufacturing the first aircraft subassembly at least partially on afirst assembly line (e.g., first assembly line 130) and manufacturingthe second aircraft subassembly at least partially on a second assemblyline (e.g., second assembly line 132). In some such examples, the firstassembly line is included in the first manufacturing zone and the secondassembly line is included in the second manufacturing zone.

Manufacturing the aircraft subassemblies at 502 comprises manufacturingthe aircraft subassemblies at the same rate such that they are producedand transferred to the third manufacturing zone at approximately thesame time. When manufacturing the first aircraft subassembly and thesecond aircraft subassembly on the first and second assembly lines,methods 500 optionally include advancing the first aircraftsubassemblies on the first assembly line and the second aircraftsubassemblies on the second assembly line at the same average velocityto achieve the same production rate and provide the aircraftsubassemblies to the third manufacturing zone at approximately the sametime.

As already discussed above, manufacturing constituent parts in the samegeographic region reduces assembly delays and increases productionrates. In particular, by manufacturing the constituent parts in the samegeographic region, aircraft subassemblies may be delivered to the finalassembly facility (e.g., third manufacturing zone) more concurrently(i.e., just in time) and/or more reliably, thereby enabling assembly tobegin more immediately and/or more frequently. In this way, finalassembly of the aircraft assembly is not subject to unexpected delays(e.g., third party manufacturer delays, shipping delays, etc.). Theentire production of the aircraft assembly may be more streamlined andconsistent, and down time may be reduced.

Manufacturing at 502 optionally includes manufacturing (or assembling)the aircraft subassemblies at least partially on fractional pulseassembly lines (e.g., fractional pulse assembly lines 126) at 504. Insome such examples, the assembly lines include the fractional pulseassembly lines. Methods 600 illustrated in FIG. 5 provide examples forfractionally pulsing constituent parts (e.g., constituent parts 200) ofthe aircraft assemblies. Thus, in some examples, at least a portion ofmethods 600 are performed at 504 of methods 500. Additionally oralternatively, manufacturing at 502 optionally includes providing baseparts (e.g., base parts 202) to the manufacturing zones at 506. Asdiscussed above, the providing includes delivering the base parts to themanufacturing zones via transportation devices (e.g., transportationdevices 100), such as land-based vehicles (e.g., trucks, vans, buses,trains), in some examples. The providing base parts to the manufacturingzones at 506 may include providing the base parts to assembly lines(e.g., assembly lines 120) and/or to feeder lines (e.g., feeder lines140). As discussed above, the feeder lines include drive mechanisms(e.g., drive mechanism 122) that propel the parts down the feeder lines,towards the assembly lines. Optionally at 512, methods 500 includemanufacturing the aircraft subassemblies in separate buildings (e.g.,buildings 14). As an example, the first manufacturing zone and thesecond manufacturing zone are included in different buildings that arephysically separated from one another, and manufacturing the aircraftsubassemblies in these two manufacturing zones includes manufacturingthe aircraft subassemblies in different buildings.

In some examples, methods 500 include producing different types ofconstituent parts in their final orientation and/or delivering thesedifferent types of constituent parts to the third manufacturing zone inthis final orientation. As an example, first assembly line is configuredto deliver the left-side wing in a final left-side wing orientation tothe third manufacturing zone and deliver the right-side wing in a finalright-side wing orientation to the final assembly facility (e.g., thirdmanufacturing zone). The left-side wing is configured to be coupled tothe fuselage in the final left-side wing orientation, and the right-sidewing is configured to be coupled to the fuselage in the final right-sidewing orientation. In this way, the wing may not need to be rotated orpivoted in the third manufacturing zone and/or when transferring thewings to the third manufacturing zone. The wings may be output by thefirst manufacturing zone in their final orientation, so that furthermanipulation is not required before final assembly.

Methods 500 include combining the aircraft subassemblies in the samegeographic region at 520. As an example, combining at 520 includesassembling the aircraft subassemblies in a third manufacturing zone(e.g., third manufacturing zone 60), that is in the same geographicregion as the first manufacturing zone and the second manufacturingzone, to form the aircraft assembly. Optionally, combining at 522includes transferring the aircraft subassemblies to the thirdmanufacturing zone. As an example, the transferring includes moving theaircraft subassemblies from one or more of the first manufacturing zone,the second manufacturing zone, and/or a fourth manufacturing zone (e.g.,fourth manufacturing zone 80) to the third manufacturing zone via one ormore transportation devices. As just one such example, and as alreadydescribed above, the transferring includes hoisting the first aircraftsubassembly with a crane from the first manufacturing zone to the thirdmanufacturing zone.

In some examples, methods 500 optionally include pulsing the aircraftsubassemblies and/or the aircraft assembly through the thirdmanufacturing zone down a third assembly line (e.g., third assembly line134) at 524. In some such examples, the pulsing includes fractionallypulsing the aircraft subassemblies and/or the aircraft assembly in asimilar manner to that described at 504.

FIG. 6 illustrates methods 600 for fractionally pulsing one or moreconstituent parts of the aircraft assembly, and thus methods 600 alsomay be described as methods for repetitively manufacturing aircraft. Themethods 600 and/or portions thereof may be used to fractionally pulseconstituent parts of the aircraft assembly at various locations in amanufacturing system (e.g., aircraft manufacturing systems 10). Thus,although the methods 600 may be utilized to fractionally pulseconstituent parts along a main assembly line (e.g., assembly lines 120),the methods 600 may additionally or alternatively be utilized tofractionally pulse constituent parts along tributary assembly lines,such as subassembly lines, towards the main assembly line, feeder lines(e.g., feeder lines 140) towards the main assembly lines and/or alongsub-feeder lines towards the feeder lines. Thus, the fractional pulseassembly lines may be configured to pulse an aircraft assembly (e.g.,aircraft assembly 78), aircraft subassemblies (e.g., first aircraftsubassembly 38, second aircraft subassembly 58, etc.) and/orsub-components, sub-structures, and constituent parts thereof. Further,the methods 600 may be utilized to fractionally pulse the aircraftassembly and/or aircraft subassemblies in a final assembly zone (e.g.,third manufacturing zone 60).

At 602, methods 600 optionally include placing one or more constituentparts (e.g., sub-components 404, base parts 202, and/or subassemblyparts 204) on the same and/or different fractional pulse assemblyline(s). At 604, methods 600 include fractionally pulsing the one ormore constituent parts down the same and/or different fractional pulseassembly line(s). In some examples, the fractionally pulsing comprisespropelling the one or more constituent parts with a drive mechanism(e.g., drive mechanism 122). The fractional pulsing comprisesperiodically pulsing (pulsing one or more constituent parts and thenwaiting a duration before pulsing the one or more constituent partsagain) the one or more constituent parts down the assembly line(s) byless than a length of the one or more constituent parts. The pulsingitself comprises propelling, translating, and/or otherwise moving theone or more constituent parts down the assembly line(s) by less than alength of the one or more constituent parts during a single pulse. Thewaiting the duration comprises waiting a time interval. In someexamples, the time interval comprises an amount of time needed tocomplete a work process on the one or more constituent parts.

Optionally at 605, the fractional pulsing includes fractionally pulsing(i.e., sending) different types of constituent parts in series down thesame assembly line or feeder line and/or producing different types ofconstituent parts in series on the same assembly line or feeder line. Asdiscussed in greater detail below, it may be determined that differenttypes of components share enough similarities and/or their workprocesses share enough similarities, that they may be pulsed down thesame assembly line or feeder line in series and/or produced on the sameassembly line or feeder line. In some examples, different aircraftsubassembly precursors may be pulsed down the same assembly line. Asexamples, left and right wings, and/or constituent parts thereof such asprecursors of the left and right wings, may be pulsed down the sameassembly line or feeder line and/or produced in series on the sameassembly line or feeder line. As another example, different sections ofa fuselage, and/or constituent parts thereof, may be pulsed down thesame assembly line or feeder line and/or produced in series on the sameassembly line or feeder line.

Different types of components are different from one anotherstructurally, functionally, and/or physically (e.g., in shape, geometry,size, etc.). As examples, a left wing and a right wing are differenttypes of components because their geometries are different (i.e., mirrorimages of one another). As another examples, different sections offuselage (e.g., forward main cabin portion 308 vs. aft main cabinportion 314) are different types of components because they may bedifferent shapes, sizes (e.g., lengths), may include different numbersof windows and/or different positions of the windows, etc. Thus, in someexamples, a given assembly line produces two different types ofconstituent parts.

By producing and/or pulsing different types of components on the sameline (assembly line or feeder line), the same work-performing devicesmay be utilized to produce the different types of components. Thisreduces the number of workers, robots, machines, and/or tools needed toproduce the aircraft assemblies, and thus reduces the cost of theaircraft manufacturing systems. Further, even where different tools maybe needed to produce the different types of components, the same workersmay still be utilized to produce the different types of components,which reduces costs. At 606, methods 600 include simultaneouslyperforming different work processes on different sections of the one ormore constituent parts. The performing different work processes includesone or more of utilizing different work-performing devices (e.g.,work-performing device 420) to perform the work, performing differenttypes of work (e.g., drilling holes vs. painting vs. laminating vs.ablating vs. attaching constituent parts, etc.), and/or performing workon different areas of the same section of a given constituent part. Inparticular, the performing the different work processes on differentsections of the one or more constituent parts includes performingdifferent work processes at different workstations (e.g., workstations410). In such examples, two or more of the workstations are configuredto perform different types of work on a given constituent partsimultaneously. Further, the two or more of the workstations areconfigured to be close enough together such that a given constituentpart occupies the two or more of the workstations at the same time.Thus, the fractional pulsing of methods 600 includes occupying at leasttwo workstations simultaneously with at least one of the one or moreconstituent parts and/or performing work on at least one of the one ormore constituent parts simultaneously at least at two or moreworkstations.

By fractionally pulsing the one or more constituent parts and performingdifferent work processes simultaneously on the one or more constituentparts, parallel processing may be increased, and productioninefficiencies may be reduced. In particular, more work may be performedon the one or more constituent parts at any given time. Further,breaking the one or more constituent parts down into fractional sectionsreduces an amount of movement of the work-performing devices needed tocomplete the work processes. Such reduced movement increases productionefficiency as well.

The performing work on the one or more constituent parts optionallyincludes removing material from the one or more constituent parts at608, adding material to the one or more constituent parts at 610, and/orprocessing, cleaning, curing, and/or otherwise exposing the one or moreconstituent parts to external stimuli (e.g., changes in pressure,changes in temperature, electromagnetic radiation, etc.) at 612. In someexamples, the adding material to the one or more constituent parts at610 includes coupling a base part (e.g., base part 202) and/orsubassembly part (e.g., subassembly part 204) to the one or moreconstituent parts. In particular, the base part and/or subassembly partmay be coupled to an aircraft subassembly precursor (e.g., aircraftsubassembly precursor 206). In some examples, the base part and/orsubassembly part is introduced to the fractional pulse assembly line viaone or more feeder lines, as discussed above in the description ofmethods 500 of FIG. 5 . Optionally at 611, the adding material includesadding a part (e.g., base part) to the one or more of the constituentparts from one or more of the feeder lines.

Optionally at 614, methods 600 include removing the one or moreconstituent parts from the fractional pulse assembly line(s), and/ormerging different assembly lines (e.g., two or more fractional pulseassembly lines) together at 615. The merging the different assemblylines may include joining the different assembly lines to form a commonassembly line. Additionally or alternatively, the merging may includejoining a tributary assembly line and/or subassembly line with a mainassembly line.

Optionally at 616, methods 600 include combining the one or moreconstituent parts to form a constituent part assembly. Combining the oneor more constituent parts at 616 includes coupling the one or moreconstituent parts together, in some examples. As one example, thecombining may include combining a base part and/or a subassembly partwith an aircraft subassembly precursor on a main assembly line. Thecoupling is achieved through the use of fasteners, adhesives, and/orother coupling mechanisms. In some examples, the methods 600 include oneor more of placing the constituent part assembly back on the assemblyline(s), fractionally pulsing the constituent part assembly down theassembly line(s), and/or fractionally pulsing the constituent partassembly down the common assembly line.

Thus, methods 600 may include assembling, coupling, and/or otherwisecombining constituent parts together. In some examples, this may be doneby taking the constituent parts of an assembly line, combining them, andthen putting them back on the same assembly line or placing them on adifferent assembly line. In other examples, this assembling, coupling,and/or otherwise combining may be performed on the assembly line withouthaving to take the constituent parts off the assembly line. In stillfurther examples, constituent parts from a first assembly line (e.g.,feeder lines 140) may be transferred to a second assembly line (e.g.,assembly lines 120) and assembled, coupled, and/or otherwise combinedwith the parts from the second assembly line on the second assemblyline. As an example, a smaller, sub-feeder assembly line may merge witha larger, main assembly line when constituent parts are to be attachedto a larger base structure, such as the aircraft subassembly precursor(e.g., when wing flaps are to be attached to the rest of the wings). Insome examples, the first assembly may merge and/or join with the secondassembly line such that the constituent parts may be transferred to thesecond assembly line via the conveyor mechanism of the first assemblyline.

In this way, aircraft subassemblies may be manufactured from base partsat least in part by fractionally pulsing the aircraft subassembliesand/or one or more of their constituent parts down one or more assemblylines and/or feeder lines.

FIG. 6 illustrates methods 700 for designing and/or constructingaircraft manufacturing systems of the present disclosure that includefractional pulse assembly lines. At 702, methods 700 include determiningand/or back-calculating constituent part production rates (i.e., takttime) based on one or more of aircraft assembly (e.g., aircraft assembly78) takt time, and the number of constituent parts. The aircraftassembly takt time is the customer demanded production rate (e.g.,number of aircraft assemblies per unit time), which is effectively theproduction rate or frequency at which the aircraft assemblies areproduced. For example, when one of the aircraft assembly (e.g., aircraft300) is produced every four hours to meet customer demand, the takt timeof the aircraft assembly is four hours. Based on the takt time of theaircraft assembly, the takt time for each of the types of constituentparts of the aircraft assembly is back-calculated based on the number ofeach type of constituent part. In particular, the back-calculating isiteratively performed backwards from component to sub-component, untilthe takt time for all of the constituent parts is calculated, in someexamples. The more sub-components a component includes, the shorter thetakt time for the sub-components. That is, when a component comprisestwo or more sub-components, the sub-components have a shorter takt timethan the component’s takt time to maintain the component’s takt time.Continuing with the above aircraft assembly example, since the aircraftassembly includes two wings (a left-side wing and a right-side wing) thetakt time for the wings must be less than the takt time for the aircraftassembly to maintain the takt time of the aircraft assembly since thereare more wings than aircraft assemblies (e.g., a wing must be deliveredto final assembly every two hours so that a full set of two wings isdelivered every four hours).

At 703, methods 700 include determining how many assembly lines (e.g.,fractional pulse assembly lines) to include in the aircraftmanufacturing system. The determining at 703 may be based on thefeasibility of manufacturing the constituent parts on an assembly line,the number of constituent parts to be produced, an amount of similaritybetween the constituent parts to be produced, and/or an amount ofsimilarity in the work processes to be performed on the constituentparts to be produced. The number of assembly lines may be affected bythe number of constituent parts for which it is actually feasible tomanufacture using assembly lines. As an example, it may not be feasibleto manufacture the third aircraft subassemblies on an assembly linebecause of their unique physical characteristics (geometry, shape, size,surface features, etc.), and/or because of the unique work processes tobe performed on them and/or their constituent parts. Thus, the thirdaircraft subassemblies may be manufactured in stationary bays (e.g.,stationary bays 84) and may not be manufactured on assembly lines.

Additionally or alternatively, the number of assembly lines to includein the aircraft manufacturing system may be affected by the number ofconstituent parts that are produced. As an example, since it may befeasible to manufacture both the first aircraft subassemblies and thesecond aircraft subassemblies on assembly lines, at least two assemblylines may be included, one assembly line (e.g., first assembly line 130)to manufacture the first aircraft subassemblies, and another assemblyline (e.g., second assembly line 132) to manufacture the second aircraftsubassemblies.

Additionally or alternatively, the number of assembly lines to includein the aircraft manufacturing system may be affected by an amount ofsimilarity between the constituent parts to be produced, and/or anamount of similarity in the work processes to be performed on theconstituent parts to be produced. This is because constituent parts thatare similar enough in their physical characteristics and/or their workprocesses to be performed may, in some examples, be manufactured on thesame assembly line. As described below at step 707 for example, left-and right-side wings may both be produced on the same assembly line(e.g., first assembly line 130). As another example, different sectionsof the fuselage may be similar enough that they may be produced on thesame assembly line (e.g., second assembly line 132). Thus, in someexamples, the aircraft manufacturing system includes two assembly lines,wherein each of the assembly lines is configured to produce two or moredifferent types of constituent parts of the aircraft. In this way, whenmore of the constituent parts may be manufactured on the same assemblyline, fewer assembly lines may be included in the aircraft manufacturingsystem.

At 704, methods 700 include determining the line lengths of thefractional pulse assembly lines of the aircraft manufacturing systembased on one or more of the following line parameters. As an example, at706, methods 700 optionally include determining the line length based onwhether constituent parts are produced in series or parallel. Inparticular, the line length is shorter when constituent parts areproduced in parallel on separate lines. As an example, the fractionalpulse assembly lines of the first manufacturing zone and the secondmanufacturing zone are in parallel with one another and thus have ashorter collective line length than they would have if they were inseries with one another.

In some examples, methods 700 at 706 optionally include determiningwhether to produce different constituent parts on the same assembly line(in series), or on different assembly lines (in parallel) at 707. Insome examples, this determination is based on at least an amount ofsimilarity between the constituent parts (e.g., similarity in size,shape, geometry, and/or other physical characteristics) and/or an amountof similarity in the work processes to be performed on the constituentparts (e.g., holes to be drilled, painting, curing, fastening,assembling of constituent parts, etc.).

As an example, a left-side wing (e.g., left wing 322) and a right-sidewing (e.g., right wing 324) are produced on the same assembly line, insome examples, for at least the reasons that the same and/or similarwork processes are performed on both wings and/or because the physicalproperties of the wings (e.g., size, shape, etc.) are similar enough toone another to be manufactured on the same assembly line. In some suchexamples, both wings are produced on the first assembly line of thefirst manufacturing zone. As another example, a forward main cabinportion of a fuselage of the aircraft assembly (e.g., forward main cabinportion 308 of fuselage 302) and an aft main cabin portion of thefuselage (e.g., aft main cabin portion 314) are produced on the sameassembly line, in some examples, for at least the reasons that the sameand/or similar work processes are performed on both the fuselage sectionand/or because the physical properties of the fuselage sections (e.g.,size, shape, color, etc.) are similar enough to one another to bemanufactured on the same assembly line. In particular, the fuselagesections have the same and/or similar semi-cylindrical shape, in someexamples. In some such examples, both fuselage sections are produced onthe second assembly line of the second manufacturing zone. As yetanother example, a tail portion (e.g., tail portion 316) of the fuselageincludes two frustoconical sections, in some examples. In some suchexamples, because of their similarity in shape, these two fuselagesections additionally or alternatively are manufactured in series on thesame assembly line. Additionally or alternatively, the determining at707 is based on takt time. In particular, in some examples, processingthe constituent parts in series on the same line may take more time thanprocessing the constituent parts in parallel on different lines. In somesuch examples, the constituent parts may need to be processed inparallel on separate lines in order to meet takt time.

The determining at 707 additionally or alternatively is based on thespacing of a work process along the length of the constituent parts. Asintroduced above, a given work process may be performed repeatedly ondifferent parts of a constituent part at a given workstation byfractionally pulsing the constituent part in sections past theworkstation. In particular, the work process may be performed at regularintervals along the length of the constituent part (e.g., windows may beinstalled every X meters along the fuselage skin) as the differentsections of the constituent part are fractionally pulsed past theworkstation. In some such examples, the regular intervals are equal tothe pulse length. In such examples, the work process may be performed inseries with the other work stations on an assembly line when the regularinterval of the work process is equal to, an integer multiple of, and/ora ⅟X fraction of the pulse length of the assembly line (and the regularintervals of the other work processes on the assembly line).

In this way, different work processes may be similarly divisible alongthe length of the constituent part on the same assembly line, such thatthe regular intervals at which the work processes are performed alongthe length of the constituent part are equal to one another, are integermultiples of one another, and/or are ⅟X fractions of one another. If awork process cannot be divided into regular intervals that are equal to,integer multiples of, and/or ⅟X fractions of the regular intervals ofthe other work processes, and/or the pulse length, of the assembly line,then the work process may need to be performed on a different assemblyline and/or a different section of the assembly line that has adifferent pulse length and/or frequency.

Thus, the determining whether work processes may be performed in seriestogether (on the same portion of the same assembly line) at 707 may bebased on the similarity in the divisibility of the work processes alongthe length of the constituent parts to be worked on. Specificallydetermining whether work processes may be performed in series togetheron the same portion of the same assembly line (i.e., whetherworkstations may be adjacently positioned next to one another on theassembly line) may be based on whether the work process may be performedat regular intervals along the length of the constituent parts that areequal to, integer multiples of, and/or ⅟X fractions of one another.

The determining at 704 additionally or alternatively is based onphysical characteristics of the sub-components being pulsed down thefractional pulse assembly line. As examples, methods 700 optionallyincludes determining the line length based on one or more of asub-component part length at 708, a number of sub-components in acomponent at 709, a size of gaps between adjacent sub-components inseries on the line at 710, and/or a number of gaps betweensub-components in series on the line at 712. In particular, the linelength is longer when the sub-components are longer, there are moresub-components in series on the line, there are more gaps betweensub-components in series on the line, and/or the size of those gaps islarger.

Additionally or alternatively, the line length is determined at 704based on the workstations. As examples, methods 700 optionally includedetermining the line length based on one or more of the size of theworkstations at 714, the number of workstations at 716, and/or thenumber and/or size of the gaps between workstations at 718. The linelength is longer when there are more workstations, when the workstationsare larger (e.g., wider), and/or when there are more and/or larger gapsbetween the workstations because more and/or larger workstations and/orgaps increase the distance the constituent parts must travel to passthrough all of the workstations on the fractional pulse assembly line.

In some examples, the size of the workstations, the number ofworkstations, and/or the number and/or size of the gaps betweenworkstations is/are determined based on a divisibility of theconstituent parts and/or on workspace constraints. As an example, whenthe constituent parts are divisible into more sections, the number ofworkstations that may be squeezed along a length of the constituent partto perform work on the constituent part at the same time, increases.However, the number of workstations that may perform work on theconstituent part at the same time is limited by the physical size of thework-performing devices. That is, the work-performing devices may limitthe amount that the workstations may be shrunk to accommodate moreworkstations, and in some examples, the workstations may be no smallerthan the size of the work-performing devices.

The divisibility of the constituent parts into smaller sections isdetermined based on one or more of an amount of similarity in thephysical characteristics of the constituent parts along a length of theconstituent parts, where the work processes are to be performed on theconstituent parts along the length of the constituent parts (i.e., thelocations on the constituent parts at which the work processes are to beperformed), and/or a repeatability of the work process along a length ofthe constituent parts (i.e., an amount of similarity in a given workprocess to be performed on the constituent parts along a length of theconstituent parts). For example, constituent parts may be broken downinto increasingly shorter sections, until a given process (e.g.,drilling) becomes too dissimilar at the different sections of theconstituent part such that it is impractical for the process to beperformed at all the sections in series (e.g., the work process is nolonger repeatable at each of the sections). Thus, the determining at 704optionally includes determining a minimum common section length at whicha constituent part may be broken down into while still maintainingenough similarity between the sections of the constituent part to havethe same work process performed on all of the sections of theconstituent part in series.

As discussed previously, reducing workstation size may increase workersafety for at least the reason that it may reduce the size of thework-performing devices handled by workers and/or reduce the amount theworkers need to move to perform the work processes. Further, increasingthe number of workstations that simultaneously perform work on theconstituent part may increase parallel processing of the part and/orincrease production efficiencies since less movement may be required toperform the work processes.

At 720, methods 700 include determining an average line velocity. Thedetermining the average line velocity is based on the takt time. Inparticular, the average line velocity is the average line velocityneeded to meet takt time, in some examples. In some such examples, thedetermining the average line velocity takes into account scheduledworker breaks, maintenance of work-performing devices at theworkstation, gaps in the assembly line (e.g., such as at an assemblyarea (e.g., assembly area 430) where various sub-components areassembled into a component), and/or parallel vs. series processing ofparts. In particular, series processing of parts at these gaps/breaks inthe assembly line may create bottlenecks that necessitate in increase inthe average line velocity of the assembly line.

By taking worker breaks, maintenance, and/or other scheduled gaps in theline where work processes are not performed into account, the line maycontinue to move, despite no work being performed on one or more of theconstituent parts on the line. By keeping the line fractionally pulsingsubstantially continuously and/or pulsing the constituent parts on theline more regularly, uncompleted work processes may be more readilyidentified because a holdup in a continuously pulsing line is morevisible (i.e., components downstream of the holdup may continue to move,whereas components upstream of the holdup may stop, thus providing avisible indication of where the holdup occurred). In this way,workstation non-performance may be more easily and readily identifiedand corrected than conventional manufacturing approaches whereconstituent parts are not pulsed regularly, or are pulsed regularly butat much longer time intervals. In some examples, small time buffers maybe created between work processes to accommodate for slight delays inwork processes. However, for lengthier delays, line movement may stopupstream of the holdup, allowing a supervisor to readily identify andremedy the holdup.

At 722, methods 700 include determining a pulse length based on one ormore of a minimum workstation length and/or a minimum section length ofconstituent parts. As discussed above at 704, the minimum workstationlength may be limited by the physical size of the work-performingdevices, and/or spacing required between work-performing devices. Theminimum section length of the constituent parts may be determined basedon the divisibility of the work process along the length of theconstituent part (i.e., how many regular intervals along the length ofthe constituent part a given work process may be performed in the sameor substantially the same manner). The divisibility of the work processin turn may be determined based on a uniformity of the constituent partsalong a length of the constituent parts (the different sections of theconstituent parts), and/or a uniformity of the work processes to beperformed along the length of the constituent parts. As introducedabove, the constituent parts may be broken down into equal lengthsections and the same and/or similar work process may be performedrepeatedly on each of the sections of the constituent part by pulsingthe constituent part past the workstation at a constant pulse lengthand/or frequency. Thus, this pulse length may be equal to, an integermultiple of, and/or a ⅟X fraction of the length of each of the sectionsof the constituent part. In this way, the work process may be performedrepeatedly in the same and/or similar manner at regular intervals alongthe length of the constituent part.

Additionally or alternatively, the pulse length is equal to the minimumworkstation length, and/or an integer multiple thereof. Thus, in suchexamples, the constituent parts are pulsed by no less than the length ofthe smallest workstation and/or by no less than the shortest section ofthe constituent parts.

In some examples, the pulse length is determined based on thedivisibility of the work process along the length of the constituentparts.

At 724, methods 700 include determining a pulse frequency based on oneor more of the average line velocity, the line length, and/or the pulselength. In particular, the pulse frequency may be the frequency neededto achieve the average line velocity given the line length and the pulselength. In particular, the line length may be divided by average linevelocity to provide a total line time. The line length may be divided bythe pulse length to determine the number of pulses on the line. Thenumber of pulses divided by the total line time provides the pulsefrequency (i.e., number of pulses per unit of time). The pulse period(e.g., pulse period 462) is then the time period between each pulse andmay include both the work period during which work is performed on theconstituent part and the time it takes to pulse the constituent part(e.g., pulse duration 466).

At 726, methods 700 optionally include constructing the assembly linebased on one or more of the above specifications (e.g., line length,pulse length, pulse frequency, etc.).

Illustrative, non-exclusive examples of inventive subject matteraccording to the present disclosure are described in the followingenumerated paragraphs:

A. An aircraft manufacturing system for repetitively manufacturingaircraft assemblies, wherein each aircraft assembly comprises at least afirst aircraft subassembly and a second aircraft subassembly, theaircraft manufacturing system comprising:

-   a first manufacturing zone configured to repetitively manufacture    first aircraft subassemblies;-   a second manufacturing zone configured to repetitively manufacture    second aircraft subassemblies; and-   a third manufacturing zone configured to receive the first aircraft    subassemblies from the first manufacturing zone, to receive the    second aircraft subassemblies from the second manufacturing zone,    and to repetitively assemble the first aircraft subassemblies and    the second aircraft subassemblies into the aircraft assemblies.

A1. The aircraft manufacturing system of paragraph A, wherein:

-   the aircraft assemblies are aircraft;-   the first aircraft subassemblies are wings; and-   the second aircraft subassemblies are fuselage sections.

A1.1 The aircraft manufacturing system of paragraph A1, wherein thefuselage sections comprise main cabin portions of the fuselage.

A2. The aircraft manufacturing system of any of paragraphs A-A1.1,wherein the first manufacturing zone and the second manufacturing zoneare substantially parallel to one another such that an overall flowdirection of the first aircraft subassemblies within the firstmanufacturing zone is substantially parallel to an overall flowdirection of the second aircraft subassemblies within the secondmanufacturing zone.

A3. The aircraft manufacturing system of any of paragraphs A-A2, whereinthe first manufacturing zone comprises a first assembly line and whereinthe second manufacturing zone comprises a second assembly line.

A3.1. The aircraft manufacturing system of paragraph A3, wherein thefirst assembly line and the second assembly line each include a conveyorsystem, and wherein a conveyor system of the first assembly line isconfigured to advance the first aircraft subassemblies along the firstassembly line within the first manufacturing zone, and wherein aconveyor system of the second assembly line is configured to advance thesecond aircraft subassemblies along the second assembly line within thesecond manufacturing zone.

A3.2. The aircraft manufacturing system of any of paragraphs A3-A3.1,wherein the first assembly line and the second assembly line compriseworkstations where work is performed on constituent parts of theaircraft assembly, and wherein work processes performed at adjacentworkstations are different.

A3.2.1. The aircraft manufacturing system of paragraph A3.2, whereinadjacent workstations comprise different robots, different machinesand/or different manufacturing personnel.

A3.2.2. The aircraft manufacturing system of any of paragraphsA3.2-A3.2.1, wherein the workstations are shorter than the firstaircraft subassemblies and the second aircraft subassemblies, such thattwo or more of the workstations perform work on the same subassemblysimultaneously.

A3.2.3. The aircraft manufacturing system of paragraph A3.2.2, whereinthe lengths of the workstations are non-uniform.

A3.2.4. The aircraft manufacturing system of any of paragraphsA3.2-A3.2.3, wherein each of the workstations of the first assembly lineperform a unique type of work process and/or wherein each of theworkstations of the second assembly line perform a unique type of workprocess.

A3.2.5. The aircraft manufacturing system of any of paragraphsA3.2-A3.2.3, wherein each of the workstations of the first assembly lineperform exactly one work process and/or wherein each of the workstationsof the second assembly line perform exactly one work process.

A3.3. The aircraft manufacturing system of any of paragraphsA3.1-A3.2.3, wherein the conveyor system of the first manufacturing zoneis configured to fractionally pulse the first aircraft subassembliesforward along the first assembly line, and wherein the conveyor systemof the second manufacturing zone is configured to fractionally pulse thesecond aircraft subassemblies forward along the second assembly line.

A3.3.1. The aircraft manufacturing system of paragraph A3.3 whendepending from any of paragraphs A3.2-A3.2.3, wherein the conveyorsystem of the first manufacturing zone is configured to advance thefirst aircraft subassemblies by at most a minimum length of theworkstations during each pulse, and wherein the conveyor system of thesecond manufacturing zone is configured to advance the second aircraftsubassemblies by at most a minimum length of the workstations duringeach pulse.

A3.4. The aircraft manufacturing system of any of paragraphs A3-A3.3.1,wherein the first aircraft subassemblies include both a left-side wingand a right-side wing.

A3.4.1. The aircraft manufacturing system of paragraph A3.4, wherein thefirst assembly line is configured to deliver the left-side wing in afinal left-side wing orientation to the third manufacturing zone anddeliver the right-side wing in a final right-side wing orientation tothe third manufacturing zone.

A3.4.1.1. The aircraft manufacturing system of paragraph A3.4, whereinthe left-side wing is configured to be coupled to a fuselage in thefinal left-side wing orientation, and wherein the right-side wing isconfigured to be coupled to the fuselage in the final right-side wingorientation.

A4. The aircraft manufacturing system of any of paragraphs A3.1-A3.2.1,wherein the first manufacturing zone and the second manufacturing zonecomprise doorways that are configured to permit the constituent parts tobe delivered to the workstations.

A4.1. The aircraft manufacturing system of paragraph A4, wherein thefirst manufacturing zone and the second manufacturing zone includefeeder lines that are configured to one or more of orient theconstituent parts in a desired orientation and advance the constituentparts away from the doorways and/or towards the first assembly line orsecond assembly line.

A5. The aircraft manufacturing system of any of paragraph A-A4, whereinthe first manufacturing zone and the second manufacturing zone areseparated from one another by at most 3 kilometers (km).

A5.1. The aircraft manufacturing system of paragraph A5, wherein thefirst manufacturing zone and the second manufacturing zone are separatedfrom one another by at least 10 meters (m).

A6. The aircraft manufacturing system of any of paragraphs A-A5, whereinthe third manufacturing zone is physically connected to the firstmanufacturing zone and the second manufacturing zone.

A7. The aircraft manufacturing system of any of paragraphs A-A6, whereinthe third manufacturing zone is physically detached from at least one ofthe first manufacturing zone and the second manufacturing zone.

A7.1. The aircraft manufacturing system of paragraph A7, wherein thethird manufacturing zone is physically detached from the secondmanufacturing zone.

A7.1.1. The aircraft manufacturing system of paragraph A7.1, wherein thethird manufacturing zone is separated from the second manufacturing zoneby at least 5 m and at most 3 km.

A7.2. The aircraft manufacturing system of paragraph A7, wherein thethird manufacturing zone is physically detached from the firstmanufacturing zone.

A7.2.1. The aircraft manufacturing system of paragraph A7.2, wherein thethird manufacturing zone is separated from the first manufacturing zoneby at least 5 m and at most 3 km.

A7.3. The aircraft manufacturing system of any of paragraphs A7-A7.2.1,further comprising delivery pathways extending along at least a portionof a perimeter of one of more of the first manufacturing zone, thesecond manufacturing zone, and the third manufacturing zone, wherein thedelivery pathways are configured to permit motorized vehicles to travelaround at least a portion of one or more of the first manufacturingzone, the second manufacturing zone, and the third manufacturing zone.

A7.3.1. The aircraft manufacturing system of paragraph A7.3 whendepending from any of paragraphs A4-A4.1, wherein the delivery pathwaysare configured to permit the motorized vehicles to deliver theconstituent parts to the doorways of the first manufacturing zone and/orthe second manufacturing zone.

A8. The aircraft manufacturing system of any of paragraphs A-A7.2,further comprising a hoist mechanism configured to lift the firstaircraft subassemblies from the first manufacturing zone to the thirdmanufacturing zone.

A8.1. The aircraft manufacturing system of paragraph A8, wherein thehoist mechanism comprises a crane.

A8.2. The aircraft manufacturing system of paragraph A8.2 when dependingfrom any of paragraphs A7.3-A7.3.1, wherein one or more of the deliverypathways extend underneath the hoist mechanism.

A8.3. The aircraft manufacturing system of any of paragraphs A8-A8.2when depending from A3.4.1-A3.4.1.1, wherein the hoist mechanism isconfigured to receive the left-side wing from the first manufacturingzone in the final left-side orientation and deliver the left-side wingto the third manufacturing zone in the final left-side orientation, andis configured to receive the right-side wing from the firstmanufacturing zone in the final right-side orientation and deliver theright-side wing to the third manufacturing zone in the final right-sideorientation.

A9. The aircraft manufacturing system of any of paragraphs A-A8.3,further comprising a fourth manufacturing zone configured torepetitively manufacture third aircraft subassemblies.

A9.1. The aircraft manufacturing system of paragraph A9, wherein thethird aircraft subassemblies comprise one or more of a cockpit portionof the fuselage, a tail portion of the fuselage, and an intermediatesection of the fuselage, wherein the intermediate section of thefuselage includes one or more of a wing box and an over-wing portion ofthe fuselage.

A9.2. The aircraft manufacturing system of any of paragraph A9-A9.1,wherein the third manufacturing zone is further configured to receivethe third aircraft subassemblies from the fourth manufacturing zone, andto repetitively assemble the third aircraft subassemblies with the firstaircraft subassemblies and the second aircraft subassemblies into theaircraft assemblies.

A9.3. The aircraft manufacturing system of any of paragraphs A9-A9.2,wherein the fourth manufacturing zone is positioned between the firstmanufacturing zone and the second manufacturing zone.

A9.4. The aircraft manufacturing system of any of paragraphs A9-A9.3,wherein the fourth manufacturing zone comprises hangar bays configuredto house each of the third aircraft subassemblies during assembly andmanufacture of the third aircraft subassemblies.

A9.5. The aircraft manufacturing system of any of paragraphs A9-A9.4,wherein the fourth manufacturing zone comprises doorways that areconfigured to permit constituent parts to be delivered to the hangarbays.

A9.6. The aircraft manufacturing system of paragraph A9.5, wherein thefourth manufacturing zone includes feeder lines that orient theconstituent parts in a desired orientation.

A9.7. The aircraft manufacturing system of any of paragraphs A9-A9.6,wherein the fourth manufacturing zone is substantially parallel with thefirst manufacturing zone and the second manufacturing zone such that anoverall flow direction of the third aircraft subassemblies issubstantially parallel to an overall flow direction of the firstaircraft subassemblies and an overall flow direction of the secondaircraft subassemblies.

A9.8. The aircraft manufacturing system of any of paragraphs A9-A9.7,wherein the fourth manufacturing zone is physically connected to thethird manufacturing zone.

A9.9. The aircraft manufacturing system of any of paragraphs A9-A9.7,wherein the fourth manufacturing zone is physically detached from thethird manufacturing zone.

A9.9.1. The aircraft manufacturing system of paragraph A9.9, wherein thethird manufacturing zone is separated from the fourth manufacturing zoneby at least 5 m.

A9.10. The aircraft manufacturing system of any of paragraphs A9-A9.9.1when depending from any of paragraphs A7.3-A7.3.1, wherein the deliverypathways extend around at least a portion of a perimeter of the fourthmanufacturing zone, and wherein the delivery pathways are configured topermit motorized vehicles to travel around at least a portion of theperimeter of the fourth manufacturing zone.

A.9.10.1. The aircraft manufacturing system of paragraph A9.10, whereinthe delivery pathways are configured to permit the motorized vehicles todeliver constituent parts to the doorways of the fourth manufacturingzone.

A9.11. The aircraft manufacturing system of any of paragraphsA9-A9.10.1, further comprising one or more transportation devices thatare configured to transport constituent parts to, from, and/or betweenone or more of the manufacturing zones.

A9.11.1. The aircraft manufacturing system of paragraph A9.11 whendepending from any of paragraphs A8-A8.2, wherein the one or moretransportation devices include the hoist mechanism.

A9.11.2. The aircraft manufacturing system of any of paragraphsA9.11-A9.11.1, wherein the one or more transportation devices compriseone or more of a hoist mechanism, a conveyor system, and shuttle.

A9.11.3. The aircraft manufacturing system of paragraph A9.11.2, whereinthe shuttle comprises a motorized vehicle.

A9.11.4. The aircraft manufacturing system of any of paragraphsA9.11-A9.11.2, wherein the one or more transportation devices comprise afirst transportation device that is configured to transfer the firstaircraft subassemblies between the first manufacturing zone and thethird manufacturing zone, and a second transportation device that isconfigured to transfer the second aircraft subassemblies between thesecond manufacturing zone and the third manufacturing zone.

A9.11.5. The aircraft manufacturing system of paragraph A9.11.4 whendepending from any of paragraphs A8-A8.2, wherein the firsttransportation device comprises the hoist mechanism.

A9.11.6 The aircraft manufacturing system of any of paragraphsA9.11-A9.11.5 when depending from any of paragraphs A9-A9.10, whereinthe one or more transportation devices comprise a third transportationdevice that is configured to transfer one or more of the third aircraftsubassemblies between the fourth manufacturing zone and the thirdmanufacturing zone.

A9.11.7. The aircraft manufacturing system of any of paragraphsA9.11-A9.11.6 when depending from any of paragraphs A9-A9.10, whereinthe one or more transportation devices comprise a fourth transportationdevice that is configured to transfer one or more of the third aircraftsubassemblies between the fourth manufacturing zone and the secondmanufacturing zone.

B. A method for repetitively manufacturing aircraft assemblies, themethod comprising:

-   assembling first aircraft subassemblies and second aircraft    subassemblies in parallel on separate assembly lines at a common    geographic region; and-   transferring the first aircraft subassemblies and the second    aircraft subassemblies to a final assembly facility located in the    same common geographic region.

B1. The method of paragraph B, wherein the first aircraft subassembliesare aircraft wings, and wherein the second aircraft subassemblies areportions of an aircraft fuselage.

B2. The method of paragraph B1, wherein the assembling the firstaircraft subassemblies and the second aircraft subassemblies in parallelcomprises assembling the first aircraft subassemblies and the secondaircraft subassemblies in parallel temporally and/or spatially.

B3. The method of any of paragraphs B1-B2, wherein the assembling thefirst aircraft subassemblies and the second aircraft subassemblies inparallel on separate assembly lines comprises sending the first aircraftsubassemblies and/or constituent parts thereof down a first assemblyline and sending the second aircraft subassemblies and/or constituentparts thereof down a second assembly line.

B3.1. The method of paragraph B3, wherein the assembling the firstaircraft subassemblies and the second aircraft subassemblies in parallelon separate assembly lines at a common geographic region comprises oneor more of sending different components of the first aircraftsubassemblies in series down the first assembly line and sendingdifferent components of the second aircraft subassemblies in series downthe second assembly line.

B3.1.1. The method of paragraph B3.1, wherein the sending the differentcomponents of the first aircraft subassemblies in series down the firstassembly line comprises sending both a right-side wing and a left-sidewing and/or constituent parts thereof down the first assembly line inseries.

B3.2 The method of any of paragraphs B3-B3.1.1, wherein the sending thefirst aircraft subassemblies and/or constituent parts thereof down thefirst assembly line comprises fractionally pulsing the first aircraftsubassemblies and/or the constituent parts thereof down the firstassembly line, and wherein the sending the second aircraft subassembliesand/or the constituent parts thereof down the second assembly linecomprises fractionally pulsing the second aircraft subassemblies and/orthe constituent parts thereof down the second assembly line.

B3.3. The method of any of paragraphs B3-B3.2, wherein the sending thefirst aircraft subassemblies and/or the constituent parts thereof downthe first assembly line and sending the second aircraft subassembliesand/or the constituent parts thereof down the second assembly linecomprises advancing the first aircraft subassemblies and/or theconstituent parts thereof and the second aircraft subassemblies and/orthe constituent parts thereof in parallel overall flow directions.

B3.4. The method of any of paragraphs B3-B3.3, wherein the sending thefirst aircraft subassemblies and/or the constituent parts thereof downthe first assembly line and sending the second aircraft subassembliesand/or the constituent parts thereof down the second assembly linecomprises sending the first aircraft subassemblies and/or theconstituent parts thereof and the second aircraft subassemblies and/orthe constituent parts thereof down the first assembly line and thesecond assembly line, respectively, at a common average velocity.

B3.4.1. The method of paragraph B3.4 when depending from paragraph B3.2,wherein the sending the first aircraft subassemblies and/or theconstituent parts thereof and the second aircraft subassemblies and/orthe constituent parts thereof down the first assembly line and thesecond assembly line, respectively, at the common average velocitycomprises fractionally pulsing the first aircraft subassemblies and/orthe constituent parts thereof and the second aircraft subassembliesand/or the constituent parts thereof at the common average velocity.

B4. The method of any of paragraphs B-B3.3, wherein the transferring thefirst aircraft subassemblies to the final assembly facility compriseshoisting the first aircraft subassemblies to the final assemblyfacility.

B5. The method of any of paragraphs B-B3, wherein the transferring thefirst aircraft subassemblies to the final assembly facility comprisestransferring the first aircraft subassemblies by at most 1 km.

B6. The method of any of paragraphs B-B5, further comprising feedingconstituent parts along one or more feeder lines to various positionsalong the first assembly line and/or the second assembly line,respectively.

B6.1. The method of paragraph B6, wherein the feeding the constituentparts comprises orienting the constituent parts, and advancing themtowards one or more of the first assembly line and the second assemblyline.

B6.2. The method of any of paragraphs B6-B6.1, wherein the assemblingthe first aircraft subassemblies and the second aircraft subassembliescomprises adding the constituent parts to one or more precursorstructures of one or more of the first aircraft subassemblies and thesecond aircraft subassemblies.

C. A method for repetitively manufacturing aircraft, the methodcomprising:

periodically advancing an aircraft component down an assembly line byless than a length of the aircraft component.

C1. The method of paragraph C, wherein the periodically advancingcomprises:

-   advancing the aircraft component by a pulse length that is less than    the length of the aircraft component; then-   stopping movement of the aircraft component for a duration; and then    advancing the aircraft component by the pulse length.

C2. The method of any of paragraphs C-C1, further comprising performingwork on the aircraft component at workstations during the duration whenthe aircraft component is not moving.

C2.1. The method of paragraph C2, wherein the performing work on theaircraft component comprises adding a constituent part to the aircraftcomponent, removing material from the aircraft component, and/ormodifying the aircraft component.

C2.2. The method of any of paragraphs C2-C2.1, wherein the performingwork on the aircraft component at the workstations comprises performingdifferent types of work processes at two or more of the workstations.

C.2.2.1. The method of paragraph C2.2, wherein the performing differenttypes of work processes at the two or more of the workstations comprisesperforming different types of work processes at each of theworkstations.

C.2.3. The method of any of paragraphs C2.2-C2.2.1, wherein theperforming different types of work processes at the two or more of theworkstations comprises simultaneously performing the different types ofwork processes at the two or more of the workstations.

C2.4. The method of any of paragraphs C-C.2.3, wherein the performingwork on the aircraft component at the workstations comprises performingexactly one type of work process at each of the workstations.

C3. The method of any of paragraphs C-C2.4, further comprising feedingconstituent parts to the assembly line via one or more feeder lines.

C4. The method of any of paragraphs C-C3, wherein the periodicallyadvancing comprises periodically advancing the aircraft component by thesame amount during each periodic advancement.

C5. The method of any of paragraphs C-C4, further comprising advancingthe aircraft component at a common average velocity along the assemblyline, and varying one or more of a pulse frequency and a pulse length ofthe periodic advancing at different sections of the assembly line.

C5.1. The method of paragraph C5, wherein the varying the pulsefrequency and pulse length at different sections of the assembly linecomprises:

-   at a first section of the assembly line, pulsing at a first    frequency and advancing the aircraft component a first distance    during each pulse; and-   at a second section of the assembly line, pulsing at a second    frequency that is higher than the first frequency, and advancing the    aircraft component a second distance that is less than the first    distance during each pulse.

C5.2. The method of any of paragraphs C5-C5.1, wherein the pulsefrequency and pulse length are varied based on an amount of divisibilityin a work process to be performed on the aircraft component and/or asize of one or more workstations on the assembly line.

C5.2.1. The method of paragraph C5.2, wherein the pulse frequencyincreases and the pulse length decreases for increases in thedivisibility of the work process to be performed on the aircraftcomponent and/or decreases in the size of the one or more workstations.

D. A method for designing an aircraft manufacturing system, the methodcomprising:

determining a fractional pulse length to fractionally pulse one or moreconstituent parts of an aircraft on a fractional pulse assembly linebased on one or more of a minimum workstation length of one or moreassembly line workstations and/or a minimum section length of one ormore work processes along a length of the one or more constituent parts.

D1. The method of paragraph D, wherein the minimum workstation length ofthe one or more assembly line workstations is determined based aphysical size of one or more work-performing devices included at the oneor more assembly line workstations.

D1.2. The method of paragraph D1, wherein the fractional pulse length isequal to, an integer multiple of, and/or a ⅟X fraction of the minimumworkstation length of the one or more workstations, where X is aninteger.

D2. The method of any of paragraphs D-D1.2, wherein the minimum sectionlength of the one or more work processes is determined based on adivisibility of the one or more work processes along the length of theone or more constituent parts.

D2.1. The method of paragraph D2, wherein the divisibility of the one ormore work processes along the length of the one or more constituentparts is determined based on one or more of where the one or more workprocesses are to be performed on the one or more constituent parts, anamount of similarity in a given work process to be performed on theconstituent parts along a length of the constituent parts, and an amountof similarity in one or more physical characteristics of the constituentparts along the length of the constituent parts.

D2.2. The method of any of paragraphs D2-D2.1, wherein the fractionalpulse length is one or more of equal to, an integer multiple of, and/ora ⅟X fraction of the minimum section length, where X is an integer.

D3. The method of any of paragraphs D-D2.2, further comprisingdetermining a number of assembly lines to include in the aircraftmanufacturing system based on one or more of a number of aircraftsubassemblies to manufacture, an amount of similarity in the workprocesses to be performed on the aircraft subassemblies and/orconstituent parts thereof, and an amount of similarity in the physicalcharacteristics of the aircraft subassemblies and/or constituentthereof.

D3.1 The method of paragraph D3, wherein the aircraft subassembliesinclude left- and right-side wings and/or sections of a fuselage.

D3.2. The method of any of paragraphs D3-D3.1, wherein the determininghow many assembly lines to include in the aircraft manufacturing systemincludes determining whether different types of aircraft subassembliesand/or constituent parts thereof are to be produced together on the sameassembly line or separately on different assembly lines.

D3.2.1. The method of paragraph D3.2, wherein the number of assemblylines decreases when more of the aircraft subassemblies and/orconstituent parts are produced on the same assembly line.

D3.3. The method of any of paragraphs D3-D3.2.1, wherein the determininghow many assembly lines to include in the aircraft manufacturing systemincludes determining whether different types of aircraft subassembliesand/or constituent parts thereof are to be produced in parallel and/orin series with one another.

D3.3.1. The method of paragraph D3.3, wherein the number of assemblylines increases when more of the aircraft subassemblies and/orconstituent parts are produced in parallel.

D4. The method of any of paragraphs D-D3, further comprising determininga pulse frequency based on one or more of an average velocity of thefractional pulse assembly line and the fractional pulse length.

D4.1. The method of paragraph D4, wherein the average velocity of thefractional pulse assembly line is determined based on one or more of adistance travelled by the constituent parts on the fractional pulseassembly line, a production rate of the constituent parts, and a numberof assembly lines configured to produce the constituent parts inparallel.

D4.1.1. The method of paragraph D4.1, wherein the production rate of theconstituent parts is determined based on a takt time of the aircraft anda number of the constituent parts included in the aircraft.

D4.1.2. The method of any of paragraphs D4.1-D4.1.1, wherein the averagevelocity of the fractional pulse assembly line decreases when the numberof assembly lines configured to produce the constituent parts inparallel increases.

D4.1.3. The method of any of paragraphs D4.1-D4.1.2, wherein thedistance travelled by the constituent parts on the fractional pulseassembly line is determined based on a length of the constituent parts,a length of one or more gaps separating the constituent parts on thefractional pulse assembly line, and/or a length of the fractional pulseassembly line.

D4.2. The method of any of paragraph D4-D4.1.3, wherein the fractionalpulse frequency is equal to the average velocity of the fractional pulseassembly line divided by the fractional pulse length.

D5. Building the aircraft manufacturing system designed according to themethod of any of paragraphs D-D4.2.

E1. A method for operating a fractional pulse assembly line and/or forrepetitively manufacturing aircraft, the method comprising:

fractionally pulsing a constituent part down an assembly line, whereinthe fractional pulsing comprises periodically advancing the constituentpart down the assembly line by less than a length of the constituentpart.

E2. The method of paragraph E1, wherein the fractional pulsing comprisessimultaneously performing different types of work on the constituentpart at different workstations on the assembly line.

E3. The method of any of paragraphs E1-E2, further comprisingfractionally pulsing two or more different types of constituent parts inseries with one another down the assembly line.

E4. The method of any of paragraphs E1-E3, further comprisingfractionally pulsing two or more constituent parts in parallel with oneanother down two or more different assembly lines.

E5. The method of paragraph E4, wherein the two or more differentassembly lines are located in different manufacturing zones.

E6. The method of any of paragraphs E4-E5, further comprising one ormore of merging the two or more different assembly lines to form acommon assembly line, assembling the two or more constituent parts toform a constituent part assembly, and/or fractionally pulsing theconstituent part assembly down the common assembly line.

E7. The method of any of paragraphs E4-E6, further comprising mergingthe two or more different assembly lines to form a common assembly line,wherein the fractionally pulsing two or more constituent parts inparallel with one another down two or more different assembly linescomprises pulsing the constituent parts in parallel at the same averageline velocity such that the constituent parts are provided to the commonassembly line at approximately the same time (i.e., just in time).

E8. The method of any of paragraphs E1-E6, further comprising thesubject matter of any of paragraphs B1-D5.

While the disclosure herein refers to aircraft assemblies and aircraft,the inventive subject matter herein may be applied to any manufacturedassembly constructed from multiple constituent parts. Accordingly, theterm “aircraft” herein may be replaced with one or more of the broadterms “apparatus,” “large apparatus,” “assembly,” “large assemblies,”“object,” “large object,” “manufactured assembly,” or “largemanufactured assembly” without departing from the scope of the presentdisclosure. Illustrative, non-exclusive examples of other manufacturedassemblies to which the disclosed inventive subject matter may applyinclude (but are not limited to) marine craft, ships, submarines, landvehicles, space vehicles, rail vehicles, machinery, wind turbines, andbuildings.

As used herein, the terms “adapted” and “configured” mean that theelement, component, or other subject matter is designed and/or intendedto perform a given function. Thus, the use of the terms “adapted” and“configured” should not be construed to mean that a given element,component, or other subject matter is simply “capable of” performing agiven function but that the element, component, and/or other subjectmatter is specifically selected, created, implemented, utilized,programmed, and/or designed for the purpose of performing the function.It is also within the scope of the present disclosure that elements,components, and/or other recited subject matter that is recited as beingadapted to perform a particular function may additionally oralternatively be described as being configured to perform that function,and vice versa. Similarly, subject matter that is recited as beingconfigured to perform a particular function may additionally oralternatively be described as being operative to perform that function.

As used herein, the term “and/or” placed between a first entity and asecond entity means one of (1) the first entity, (2) the second entity,and (3) the first entity and the second entity. Multiple entries listedwith “and/or” should be construed in the same manner, i.e., “one ormore” of the entities so conjoined. Other entities optionally may bepresent other than the entities specifically identified by the “and/or”clause, whether related or unrelated to those entities specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB,” when used in conjunction with open-ended language such as“comprising,” may refer, in one example, to A only (optionally includingentities other than B); in another example, to B only (optionallyincluding entities other than A); in yet another example, to both A andB (optionally including other entities). These entities may refer toelements, actions, structures, steps, operations, values, and the like.

The various disclosed elements of apparatuses and steps of methodsdisclosed herein are not required to all apparatuses and methodsaccording to the present disclosure, and the present disclosure includesall novel and non-obvious combinations and subcombinations of thevarious elements and steps disclosed herein. Moreover, one or more ofthe various elements and steps disclosed herein may define independentinventive subject matter that is separate and apart from the whole of adisclosed apparatus or method. Accordingly, such inventive subjectmatter is not required to be associated with the specific apparatusesand methods that are expressly disclosed herein, and such inventivesubject matter may find utility in apparatuses and/or methods that arenot expressly disclosed herein.

1. An aircraft manufacturing system for repetitively manufacturingaircraft assemblies, the aircraft manufacturing system comprising: afirst manufacturing zone configured to repetitively manufacture firstaircraft subassemblies, wherein the first aircraft subassemblies includeboth a left-side wing and a right-side wing; a second manufacturing zoneconfigured to repetitively manufacture second aircraft subassemblies,wherein the second aircraft subassemblies include fuselage sections; anda third manufacturing zone configured to receive the first aircraftsubassemblies from the first manufacturing zone, to receive the secondaircraft subassemblies from the second manufacturing zone, and torepetitively assemble the first aircraft subassemblies and the secondaircraft subassemblies into the aircraft assemblies; and wherein thefirst manufacturing zone comprises a first assembly line, and whereinthe first assembly line is configured to deliver the left-side wing in afinal left-side wing orientation to the third manufacturing zone anddeliver the right-side wing in a final right-side wing orientation tothe third manufacturing zone.
 2. The aircraft manufacturing system ofclaim 1, wherein the left-side wing is configured to be coupled to afuselage in the final left-side wing orientation, and wherein theright-side wing is configured to be coupled to the fuselage in the finalright-side wing orientation.
 3. The aircraft manufacturing system ofclaim 1, wherein the fuselage sections comprise main cabin portions ofthe fuselage.
 4. The aircraft manufacturing system of claim 1, whereinthe first manufacturing zone and the second manufacturing zone areseparated from one another by at most 3 kilometers (km).
 5. An aircraftmanufacturing system for repetitively manufacturing aircraft assemblies,the aircraft manufacturing system comprising: a first manufacturing zoneconfigured to repetitively manufacture first aircraft subassemblies,wherein the first aircraft subassemblies are aircraft wings; a secondmanufacturing zone configured to repetitively manufacture secondaircraft subassemblies, wherein the second aircraft subassemblies areportions of an aircraft fuselage; and a third manufacturing zoneconfigured to receive the first aircraft subassemblies from the firstmanufacturing zone, to receive the second aircraft subassemblies fromthe second manufacturing zone, and to repetitively assemble the firstaircraft subassemblies and the second aircraft subassemblies into theaircraft assemblies.
 6. The aircraft manufacturing system of claim 5,wherein the first manufacturing zone and the second manufacturing zoneare separated from one another by at most 3 kilometers (km).
 7. Theaircraft manufacturing system of claim 5, wherein the firstmanufacturing zone comprises a first assembly line, and wherein thesecond manufacturing zone comprises a second assembly line, wherein thefirst assembly line and the second assembly line comprise workstationswhere work is performed on constituent parts of the aircraft assemblies,and wherein work processes performed at adjacent workstations aredifferent.
 8. The aircraft manufacturing system of claim 7, wherein theworkstations of the first manufacturing zone are shorter than the firstaircraft subassemblies, such that two or more of the workstations of thefirst manufacturing zone perform work on the same subassemblysimultaneously.
 9. The aircraft manufacturing system of claim 8, whereinthe workstations of the second manufacturing zone are shorter than thesecond aircraft subassemblies, such that two or more of the workstationsof the second manufacturing zone perform work on the same subassemblysimultaneously.
 10. The aircraft manufacturing system of claim 7,wherein the first assembly line includes a conveyor system, and whereinthe conveyor system is configured to fractionally pulse the firstaircraft subassemblies along the first assembly line within the firstmanufacturing zone.
 11. The aircraft manufacturing system of claim 10,wherein the conveyor system is a first conveyor system, wherein thesecond assembly line includes a second conveyor system, and wherein thesecond conveyor system is configured to fractionally pulse the secondaircraft subassemblies along the second assembly line within the secondmanufacturing zone.
 12. The aircraft manufacturing system of claim 7,wherein the first manufacturing zone includes feeder lines that areconfigured to orient the constituent parts in desired orientations oradvance the constituent parts towards the first assembly line.
 13. Theaircraft manufacturing system of claim 5 further comprising a fourthmanufacturing zone configured to repetitively manufacture third aircraftsubassemblies, wherein the third manufacturing zone is furtherconfigured to receive the third aircraft subassemblies from the fourthmanufacturing zone, and to repetitively assemble the third aircraftsubassemblies with the first aircraft subassemblies and the secondaircraft subassemblies into the aircraft assemblies.
 14. The aircraftmanufacturing system of claim 5, further comprising one or more of afirst transportation device that is configured to transfer the firstaircraft subassemblies between the first manufacturing zone and thethird manufacturing zone, and a second transportation device that isconfigured to transfer the second aircraft subassemblies between thesecond manufacturing zone and the third manufacturing zone.
 15. Theaircraft manufacturing system of claim 14, wherein the firsttransportation device comprises a hoist mechanism.
 16. The aircraftmanufacturing system of claim 5, wherein the third manufacturing zone isphysically detached from at least one of the first manufacturing zoneand the second manufacturing zone.
 17. The aircraft manufacturing systemof claim 16, wherein the third manufacturing zone is physically detachedfrom the first manufacturing zone and the second manufacturing zone. 18.The aircraft manufacturing system of claim 16, further comprisingdelivery pathways extending along at least a portion of a perimeter ofone or more of the first manufacturing zone, the second manufacturingzone, and the third manufacturing zone, wherein the delivery pathwaysare configured to permit motorized vehicles to travel around at least aportion of the perimeter of one or more of the first manufacturing zone,the second manufacturing zone, and the third manufacturing zone.
 19. Theaircraft manufacturing system of claim 18, wherein the firstmanufacturing zone comprises a first assembly line and wherein thesecond manufacturing zone comprises a second assembly line; wherein thefirst assembly line includes a first conveyor system configured toadvance the first aircraft subassemblies along the first assembly linewithin the first manufacturing zone, and wherein the second assemblyline includes a second conveyor system configured to advance the secondaircraft subassemblies along the second assembly line within the secondmanufacturing zone; wherein the first assembly line and the secondassembly line comprise workstations where work is performed onconstituent parts of the aircraft assemblies, and wherein work processesperformed at adjacent workstations are different; wherein the firstmanufacturing zone and the second manufacturing zone comprise doorwaysthat are configured to permit the constituent parts to be delivered tothe workstations; and wherein the delivery pathways are configured topermit the motorized vehicles to deliver the constituent parts to thedoorways.
 20. The aircraft manufacturing system of claim 18, furthercomprising a hoist mechanism configured to lift the first aircraftsubassemblies from the first manufacturing zone to the thirdmanufacturing zone, wherein one or more of the delivery pathways extendunderneath the hoist mechanism.
 21. The aircraft manufacturing system ofclaim 5, further comprising a hoist mechanism configured to lift thefirst aircraft subassemblies from the first manufacturing zone to thethird manufacturing zone; wherein the first manufacturing zone comprisesa first assembly line, and wherein the second manufacturing zonecomprises a second assembly line; wherein the aircraft wings of thefirst aircraft subassemblies include both a left-side wing and aright-side wing; wherein the first assembly line is configured todeliver the left-side wing in a final left-side wing orientation to thethird manufacturing zone and deliver the right-side wing in a finalright-side wing orientation to the third manufacturing zone; and whereinthe hoist mechanism is configured to receive the left-side wing from thefirst manufacturing zone in the final left-side wing orientation anddeliver the left-side wing to the third manufacturing zone in the finalleft-side wing orientation, and is configured to receive the right-sidewing from the first manufacturing zone in the final right-side wingorientation and deliver the right-side wing to the third manufacturingzone in the final right-side wing orientation.
 22. The aircraftmanufacturing system of claim 5, wherein the first manufacturing zoneand the second manufacturing zone are in different buildings.
 23. Anaircraft manufacturing system for repetitively manufacturing aircraftassemblies, the aircraft manufacturing system comprising: a firstmanufacturing zone configured to repetitively manufacture first aircraftsubassemblies, wherein the first aircraft subassemblies include both aleft-side wing and a right-side wing; a second manufacturing zoneconfigured to repetitively manufacture second aircraft subassemblies,wherein the second aircraft subassemblies include fuselage sections; anda third manufacturing zone configured to receive the first aircraftsubassemblies from the first manufacturing zone, to receive the secondaircraft subassemblies from the second manufacturing zone, and torepetitively assemble the first aircraft subassemblies and the secondaircraft subassemblies into the aircraft assemblies; and wherein thefirst manufacturing zone comprises a first assembly line, and whereinthe first assembly line is configured to deliver the left-side wing in afinal left-side wing orientation to the third manufacturing zone anddeliver the right-side wing in a final right-side wing orientation tothe third manufacturing zone, and wherein the first manufacturing zoneand the second manufacturing zone are separated from one another by atmost 3 kilometers (km).